Deck 9: Hypothesis Testing: Single Population

Question 1

The Next Questions Are Based On The Following Information:
The sales representative for a manufacturer of a new product claims that the product will increase output per machine by at least 29 units per hour.A line manager installs the product on 15 of the machines,and finds that the average increase was only 26 with a standard deviation of 6.2.
Which of the following is true of confidence intervals in hypothesis tests of the variance of a normal population,where variances are smaller than anticipated?

A)It will always result in a negative value.
B)It will meet anticipated levels.
C)It will be wider than anticipated.
D)It will be narrower than anticipated.

Answer 1

It will be narrower than anticipated.

Question 2

Match the symbol α with the correct definition.

A)the power of a test
B)the probability of a Type I error
C)the probability of a Type II error
D)the probability of failing to reject the null hypothesis when it is true

Answer 2

the probability of a Type I error

Question 3

The Next Questions Are Based On The Following Information:
The sales representative for a manufacturer of a new product claims that the product will increase output per machine by at least 29 units per hour.A line manager installs the product on 15 of the machines,and finds that the average increase was only 26 with a standard deviation of 6.2.
The value of the test statistic is:

A)1.240
B)1.874
C)-1.240
D)-1.874

Answer 3

-1.874

Question 4

The Next Questions Are Based On The Following Information:
The manufacturer of a new chewing gum claims that at least 80% of dentists surveyed prefer their type of gum and recommend it for their patients who chew gum.An independent consumer research firm decides to test their claim.The findings in a sample of 200 dentists indicate that 74.1% of the respondents do actually prefer their gum.
The value of the test statistic is:

A)2.086
B)1.444
C)-2.086
D)-1.444

Question 5

The Next Questions Are Based On The Following Information:
The supervisor of a production line believes that the average time to assemble an electronic component is 14 minutes.Assume that assembly time is normally distributed with a standard deviation of 3.4 minutes.The supervisor times the assembly of 14 components,and finds that the average time for completion is 11.6 minutes.
What is the z-value for a two-sided test of hypothesis for a population mean when the probability of rejecting a true null hypothesis is equal to .05?

A)1.645
B)2.330
C)1.960
D)2.575

Question 6

The Next Questions Are Based On The Following Information:
The U.S.Postal Service advertises that at least 63.4% of all third class mail is read by the recipients.An environmental group,concerned about waste production wants to test this assertion.They take a sample of 220 households and find that only 58.7% read their third class mail.
What are the null and alternative hypotheses for the environmental group's test?

A)H₀ : P = 0.634 and H₁ : P > 0.634
B)H₀ : P = 0.634 and H₁ : P ≠ 0.634
C)H₀ : P = 0.634 and H₁ : P < 0.634
D)H₀ : P > 0.634 and H₁ : P ≤ 0.634

Question 7

The Next Questions Are Based On The Following Information:
The sales representative for a manufacturer of a new product claims that the product will increase output per machine by at least 29 units per hour.A line manager installs the product on 15 of the machines,and finds that the average increase was only 26 with a standard deviation of 6.2.
Using a 5% significance level,which of the following statements is true?

A)Reject H₀ if t statistic < 1.771
B)Reject H₀ if t statistic > 2.16
C)Reject H₀ if t statistic < -1.761
D)Reject H₀ if t statistic < -2.16

Question 8

The Next Questions Are Based On The Following Information:
The supervisor of a production line believes that the average time to assemble an electronic component is 14 minutes.Assume that assembly time is normally distributed with a standard deviation of 3.4 minutes.The supervisor times the assembly of 14 components,and finds that the average time for completion is 11.6 minutes.
What are the appropriate null and alternative hypotheses?

A)H₀ : μ ≥ 14 and H₁: μ < 14
B)H₀ : μ ≤ 14 and H₁: μ > 14
C)H₀ : μ = 14 and H₁: μ ≠ 14
D)H₀ : μ ≠ 14 and H₁: μ = 14

Question 9

The Next Questions Are Based On The Following Information:
The manufacturer of a new chewing gum claims that at least 80% of dentists surveyed prefer their type of gum and recommend it for their patients who chew gum.An independent consumer research firm decides to test their claim.The findings in a sample of 200 dentists indicate that 74.1% of the respondents do actually prefer their gum.
If conducting a two-sided test of population means,unknown variance,at level of significance 0.05 based on a sample of size 20,the critical t-value is:

A)1.725
B)2.093
C)2.086
D)1.729

Question 10

Match the symbol (1 - β)with the correct definition.

A)the power of a test
B)the probability of a Type I error
C)the probability of a Type II error
D)the probability of failing to reject the null hypothesis when it is true

Question 11

The Next Questions Are Based On The Following Information:
The supervisor of a production line believes that the average time to assemble an electronic component is 14 minutes.Assume that assembly time is normally distributed with a standard deviation of 3.4 minutes.The supervisor times the assembly of 14 components,and finds that the average time for completion is 11.6 minutes.
Which of the following statements is most accurate?

A)fail to reject the null hypothesis at α ≤ 0.10
B)reject the null hypothesis at α = 0.025,but not at α = 0.05
C)reject the null hypothesis at α = 0.05,but not at α = 0.01
D)reject the null hypothesis at α = 0.01

Question 12

The Next Questions Are Based On The Following Information:
The manufacturer of a new chewing gum claims that at least 80% of dentists surveyed prefer their type of gum and recommend it for their patients who chew gum.An independent consumer research firm decides to test their claim.The findings in a sample of 200 dentists indicate that 74.1% of the respondents do actually prefer their gum.
What is the decision rule?

A)Reject H₀ if (
- P₀)/

> z_α/2
B)Reject H₀ if (
- P₀)/

> z_α
C)Reject H₀ if (
- P₀)/

< -z_α/2
D)Reject H₀ if (
- P₀)/

< -z_α

Question 13

The Next Questions Are Based On The Following Information:
The manufacturer of a new chewing gum claims that at least 80% of dentists surveyed prefer their type of gum and recommend it for their patients who chew gum.An independent consumer research firm decides to test their claim.The findings in a sample of 200 dentists indicate that 74.1% of the respondents do actually prefer their gum.
Which of the following statements is most accurate?

A)Fail to reject the null hypothesis at α ≤ 0.10
B)Reject the null hypothesis at α = 0.05
C)Reject the null hypothesis at α = 0.10,but not 0.05
D)Reject the null hypothesis at α = 0.01

Question 14

Match the symbol β with the correct definition.

A)the power of a test
B)the probability of a Type I error
C)the probability of a Type II error
D)the probability of failing to reject the null hypothesis when it is true

Question 15

The Next Questions Are Based On The Following Information:
The sales representative for a manufacturer of a new product claims that the product will increase output per machine by at least 29 units per hour.A line manager installs the product on 15 of the machines,and finds that the average increase was only 26 with a standard deviation of 6.2.
What are the appropriate null and alternative hypotheses?

A)H₀ : μ = 29 and H₁: μ ≠ 29
B)H₀ : μ ≥ 29 and H₁: μ < 29
C)H₀ : μ = 29 and H₁: μ > 29
D)H₀ : μ > 29 and H₁: μ ≤ 29

Question 16

A professor of statistics wants to test that the average amount of money a typical college student spends per day during spring break is over $70.Based upon previous research,the population standard deviation is estimated to be $17.32.The professor surveys 35 students and finds that the mean spending is $72.43.Which of the following statements is most accurate?

A)fail to reject the null hypothesis at α ≤ 0.10
B)reject the null hypothesis at α = 0.10
C)reject the null hypothesis at α = 0.05
D)reject the null hypothesis at α = 0.01

Question 17

The Next Questions Are Based On The Following Information:
The manufacturer of a new chewing gum claims that at least 80% of dentists surveyed prefer their type of gum and recommend it for their patients who chew gum.An independent consumer research firm decides to test their claim.The findings in a sample of 200 dentists indicate that 74.1% of the respondents do actually prefer their gum.
What are the null and alternative hypotheses for the test?

A)H₀ : P ≥ 0.80 and H₁ : P < 0.80
B)H₀ : P = 0.80 and H₁ : P ≠ 0.80
C)H₀ : P ≤ 0.80 and H₁ : P > 0.80
D)H₀ : P > 0.80 and H₁ : P ≤ 0.80

Question 18

The Next Questions Are Based On The Following Information:
The sales representative for a manufacturer of a new product claims that the product will increase output per machine by at least 29 units per hour.A line manager installs the product on 15 of the machines,and finds that the average increase was only 26 with a standard deviation of 6.2.
Which of the following statements is most accurate?

A)reject the null hypothesis at α = 0.10
B)fail to reject the null hypothesis at α ≤ 0.10
C)reject the null hypothesis at α = 0.05,but not 0.10
D)reject the null hypothesis at α = 0.01,but not 0.05

Question 19

Match the symbol (1- α)with the correct definition.

A)the power of a test
B)the probability of a Type I error
C)the probability of a Type II error
D)the probability of failing to reject the null hypothesis when it is true

Question 20

The Next Questions Are Based On The Following Information:
The sales representative for a manufacturer of a new product claims that the product will increase output per machine by at least 29 units per hour.A line manager installs the product on 15 of the machines,and finds that the average increase was only 26 with a standard deviation of 6.2.
What is the critical value for an upper-tailed hypothesis test of the population mean when the population variance is unknown in which a null hypothesis is tested at the 0.05 level of significance based on a sample size of 18?

A)2.110
B)2.101
C)1.734
D)1.740

Question 21

The Next Questions Are Based On The Following Information:
The dean of a business college in the Midwest claims that he can correctly identify whether a student is a finance major or a music industry management major by the way the student dresses.Suppose in actuality that he can correctly identify finance majors 84% of the time,while 16% of the time he mistakenly identifies a music industry management major as a finance major.Presented with one student and asked to identify the major of this student (who is either a finance or music industry management major),the dean considers this to be a hypothesis test with the null hypothesis being that the student is a finance major and the alternative that the student is a music industry management major.
Which of the following statements is an example of power of the test?

A)The probability of saying that the student is a music industry management major when in fact the student is a finance major.
B)The probability of saying that the student is a finance major when in fact the student is a finance major.
C)The probability of saying that the student is a finance major when in fact the student is a music industry management major.
D)The probability of saying that the student is a music industry management major when in fact the student is a music industry management major.

Question 22

The Next Questions Are Based On The Following Information:
An accountant claims to be able to complete a standard tax return in under an hour.For a random sample of 24 tax returns,the accountant averaged 63.2 minutes with a standard deviation of 7.7 minutes.
What are the appropriate null and alternative hypotheses?

A)H₀ : μ = 60 and H₁ : μ ≠ 60
B)H₀ : μ = 60 and H₁ : μ > 60
C)H₀ : μ = 60 and H₁ : μ < 60
D)H₀ : μ > 60 and H₁ : μ ≤ 60

Question 23

The Next Questions Are Based On The Following Information:
The U.S.Postal Service advertises that at least 63.4% of all third class mail is read by the recipients.An environmental group,concerned about waste production wants to test this assertion.They take a sample of 220 households and find that only 58.7% read their third class mail.
What would the environmental group's decision rule be?

A)Reject H₀ if (
- P₀)/

< -z_α/2
B)Reject H₀ if (
- P₀)/

< -z_α
C)Reject H₀ if (
- P₀)/

> -z_α/2
D)Reject H₀ if (
- P₀)/

< -z_α

Question 24

The Next Questions Are Based On The Following Information:
A small community college claims that their average class size is equal to 35 students.This claim is being tested with a level of significance equal to 0.02 using the following sample of class sizes: 42,28,36,47,35,41,33,30,39,and 48.Assume class sizes are normally distributed.
What is the value of the test statistic?

A)1.58
B)1.36
C)2.05
D)2.26

Question 25

The Next Questions Are Based On The Following Information:
The dean of a business college in the Midwest claims that he can correctly identify whether a student is a finance major or a music industry management major by the way the student dresses.Suppose in actuality that he can correctly identify finance majors 84% of the time,while 16% of the time he mistakenly identifies a music industry management major as a finance major.Presented with one student and asked to identify the major of this student (who is either a finance or music industry management major),the dean considers this to be a hypothesis test with the null hypothesis being that the student is a finance major and the alternative that the student is a music industry management major.
An assembly line will be shut down for maintenance if the defect rate exceeds 2.3%.Suppose you adopt a 5% significance level and take a random sample of 200 items from the assembly line and compute the proportion of defective items.For what values of the sample proportion will the assembly line be shut down?

A)0.034
B)0.038
C)0.036
D)0.040

Question 26

The Next Questions Are Based On The Following Information:
The dean of a business college in the Midwest claims that he can correctly identify whether a student is a finance major or a music industry management major by the way the student dresses.Suppose in actuality that he can correctly identify finance majors 84% of the time,while 16% of the time he mistakenly identifies a music industry management major as a finance major.Presented with one student and asked to identify the major of this student (who is either a finance or music industry management major),the dean considers this to be a hypothesis test with the null hypothesis being that the student is a finance major and the alternative that the student is a music industry management major.
The manufacturer of bags of cement claims that they fill each bag with at least 50.1 pounds of cement.Assume that the standard deviation for the amount in each bag is 1.2 pounds.The decision rule is adopted to shut down the filling machine if the sample mean weight for a sample of 40 bags is below 49.7.What is the probability of a Type I error?

A)0.018
B)0.024
C)0.030
D)0.036

Question 27

The Next Questions Are Based On The Following Information:
An accountant claims to be able to complete a standard tax return in under an hour.For a random sample of 24 tax returns,the accountant averaged 63.2 minutes with a standard deviation of 7.7 minutes.
What is the most accurate estimate of the p-value?

A)0.025 < p-value < 0.05
B)0.01 < p-value < 0.025
C)0.05 < p-value < 0.10
D)p-value < 0.01

Question 28

The Next Questions Are Based On The Following Information:
A small community college claims that their average class size is equal to 35 students.This claim is being tested with a level of significance equal to 0.02 using the following sample of class sizes: 42,28,36,47,35,41,33,30,39,and 48.Assume class sizes are normally distributed.
The manufacturer of bags of cement claims that they fill each bag with at least 50.2 pounds of cement.Assume that the standard deviation for the amount in each bag is 1.2 pounds.The decision rule is adopted to shut down the filling machine if the sample mean weight for a sample of 40 bags is below 49.8.Suppose that the true mean weight of bags is 50 pounds.Using this decision rule,what is the probability of a Type II error?

A)0.85
B)0.70
C)0.80
D)0.75

Question 29

Suppose that you want to test H₀ : P = 0.25 against H₁: P ≠ 0.25.The test statistic is:

A)(
- P₀)/

B)(p - P₀)/
C)(
- P₀)/

D)(p - P₀)/ [(P₀)(1 - P₀)/ n]

Question 30

The Next Questions Are Based On The Following Information:
The dean of a business college in the Midwest claims that he can correctly identify whether a student is a finance major or a music industry management major by the way the student dresses.Suppose in actuality that he can correctly identify finance majors 84% of the time,while 16% of the time he mistakenly identifies a music industry management major as a finance major.Presented with one student and asked to identify the major of this student (who is either a finance or music industry management major),the dean considers this to be a hypothesis test with the null hypothesis being that the student is a finance major and the alternative that the student is a music industry management major.
Thomas is a shift manager at a local fast food place,and is responsible for quality management.Thomas wants to ensure that each of the frozen hamburger patties that get delivered by the supplier weighs four ounces on average.Assume that the standard deviation of the weight of hamburger patties is known to be 0.1 ounces.Thomas tells one of his employees that as a shipment comes in,select 20 patties at random and find the average weight for the 20 patties.If the average weight is less than 3.95 ounces,reject the shipment.What is the smallest significance level associated with this decision rule?

A)0.015
B)0.008
C)0.023
D)0.013

Question 31

The Next Questions Are Based On The Following Information:
The U.S.Postal Service advertises that at least 63.4% of all third class mail is read by the recipients.An environmental group,concerned about waste production wants to test this assertion.They take a sample of 220 households and find that only 58.7% read their third class mail.
Which of the following statements is most accurate?

A)Reject the null hypothesis at α = 0.10.
B)Fail to reject the null hypothesis at α ≤ 0.10.
C)Reject the null hypothesis at α = 0.05.
D)Reject the null hypothesis at α = 0.01.

Question 32

The Next Questions Are Based On The Following Information:
An accountant claims to be able to complete a standard tax return in under an hour.For a random sample of 24 tax returns,the accountant averaged 63.2 minutes with a standard deviation of 7.7 minutes.
What is the test statistic for this test?

A)Z = 2.04
B)t = 1.79
C)t = 2.04
D)Z = 1.79

Question 33

The Next Questions Are Based On The Following Information:
Suppose that you want to test H₀ = μ = 0.54 against H₁ :μ < 0.54 based on a sample of n = 25 and s = 13.2.
What is the appropriate critical value?

A)t_n-1,α/2
B)- Z_α
C)- t_n-1,α
D)Z_α/2

Question 34

The Next Questions Are Based On The Following Information:
A small community college claims that their average class size is equal to 35 students.This claim is being tested with a level of significance equal to 0.02 using the following sample of class sizes: 42,28,36,47,35,41,33,30,39,and 48.Assume class sizes are normally distributed.
Which of the following conclusions can be drawn?

A)Since the test statistics equals 1.58,reject the null hypothesis and conclude that class size does not equal 35 students.
B)Since the test statistics equals 1.36,fail to reject the null hypothesis and conclude that there's insufficient evidence to conclude that class size does not equal 35 students.
C)Since the test statistics equals 2.05,reject the null hypothesis and conclude that class size does not equal 35 students.
D)Since the test statistics equals 2.26,fail to reject the null hypothesis and conclude that class size does equal 35 students.

Question 35

The Next Questions Are Based On The Following Information:
A small community college claims that their average class size is equal to 35 students.This claim is being tested with a level of significance equal to 0.02 using the following sample of class sizes: 42,28,36,47,35,41,33,30,39,and 48.Assume class sizes are normally distributed.
Which distribution is most appropriate to perform this hypothesis test?

A)Student's t distribution
B)Normal distribution
C)F distribution
D)Chi-square distribution

Question 36

The Next Questions Are Based On The Following Information:
The dean of a business college in the Midwest claims that he can correctly identify whether a student is a finance major or a music industry management major by the way the student dresses.Suppose in actuality that he can correctly identify finance majors 84% of the time,while 16% of the time he mistakenly identifies a music industry management major as a finance major.Presented with one student and asked to identify the major of this student (who is either a finance or music industry management major),the dean considers this to be a hypothesis test with the null hypothesis being that the student is a finance major and the alternative that the student is a music industry management major.
Which of the following statements illustrates a Type II error?

A)Saying that the student is a music industry management major when in fact the student is a finance major.
B)Saying that the student is a finance major when in fact the student is a finance major.
C)Saying that the student is a finance major when in fact the student is a music industry management major.
D)Saying that the student is a music industry management major when in fact the student is a music industry management major.

Question 37

The Next Questions Are Based On The Following Information:
Suppose that you want to test H₀ = μ = 0.54 against H₁ :μ < 0.54 based on a sample of n = 25 and s = 13.2.
What is the test statistic?

A)(
- 0.54)/ 34.848
B)(
- 0.54)/ 2.64
C)(
- 0.54)/ 0.528
D)(
- 0.54)/ 0.2789

Question 38

Suppose that you want to test H₀ : P = 0.55 against H₁: P ≠ 0.55.The appropriate critical values are:

A)± z_α
B)± z_α/2
C)± t_n-1,α/2
D)± t_n-1,α

Question 39

The Next Questions Are Based On The Following Information:
The dean of a business college in the Midwest claims that he can correctly identify whether a student is a finance major or a music industry management major by the way the student dresses.Suppose in actuality that he can correctly identify finance majors 84% of the time,while 16% of the time he mistakenly identifies a music industry management major as a finance major.Presented with one student and asked to identify the major of this student (who is either a finance or music industry management major),the dean considers this to be a hypothesis test with the null hypothesis being that the student is a finance major and the alternative that the student is a music industry management major.
Which of the following statements illustrates a Type I error?

A)Saying that the student is a music industry management major when in fact the student is a finance major.
B)Saying that the student is a finance major when in fact the student is a finance major.
C)Saying that the student is a finance major when in fact the student is a music industry management major.
D)Saying that the student is a music industry management major when in fact the student is a music industry management major.

Question 40

The probability of rejecting a null hypothesis when the null hypothesis is true is known as the:

A)confidence level.
B)p-value.
C)power of the test.
D)significance level.

Question 41

The Next Questions Are Based On The Following Information:
A small community college claims that their average class size is equal to 35 students.This claim is being tested with a level of significance equal to 0.02 using the following sample of class sizes: 42,28,36,47,35,41,33,30,39,and 48.Assume class sizes are normally distributed.
A Type II error is defined as:

A)rejecting a true alternative hypothesis.
B)rejecting a true null hypothesis.
C)failing to reject a false null hypothesis.
D)failing to reject a false alternative hypothesis.

Question 42

The Next Questions Are Based On The Following Information:
A hydraulic press is operating correctly when the standard deviation of the pressure is less than 120 pounds-per-square-inch (psi).Suppose you take a random sample of 15 measurements throughout the day of the psi and find the standard deviation to be 148.Suppose you want to test whether the press is operating correctly.
Assume the following null and alternative hypotheses: H₀ : μ = μ₀ and H₁ : μ > μ₀.In addition,you know σ.Take a random sample of n observations and choose some value α.What is the decision rule for this test?

A)Reject H₀ if (
- μ₀)/ (σ /

)> z_α
B)Reject H₀ if (
- μ₀)/

< -z_α
C)Reject H₀ if (
- μ₀)/

< z_α
D)Reject H₀ if (
- μ₀)/ (σ /

)> z_α/2

Question 43

The Next Questions Are Based On The Following Information:
The state lottery office claims that the average household income of those people playing the lottery is at least $37,000.Assume that the distribution of household income of those people playing the lottery is normally distributed with a standard deviation of $5,756.Suppose that for a sample of 25 households,it is found that the average income was $36,243.
What is the test statistic for this test?

A)t = -0.66
B)Z = -0.66
C)Z = 1.92
D)t = 1.92

Question 44

The Next Questions Are Based On The Following Information:
A hydraulic press is operating correctly when the standard deviation of the pressure is less than 120 pounds-per-square-inch (psi).Suppose you take a random sample of 15 measurements throughout the day of the psi and find the standard deviation to be 148.Suppose you want to test whether the press is operating correctly.
When testing H₀ : μ = 50 against H₁ : μ ≠ 50,where would the rejection region fall for this hypothesis test?

A)in the left tail
B)in the right tail
C)in both the left and right tails
D)at point zero

Question 45

The Next Questions Are Based On The Following Information:
A professor claims that the average score on a recent exam was 83.Suppose you want to test whether the professor's statement is correct.Assume that the test scores are normally distributed.You ask some people in class how they did,and record the following scores: 82,77,85,76,81,91,70,and 82.
What is the appropriate decision rule?

A)Reject H₀ if t statistic > t_α,n-1
B)Reject H₀ if t statistic < -t_n-1,α/2 or > t_n-1,α/2
C)Reject H₀ if t statistic = t_α,n-1
D)Reject H₀ if t statistic < -t_α,n-1

Question 46

The Next Questions Are Based On The Following Information:
A hydraulic press is operating correctly when the standard deviation of the pressure is less than 120 pounds-per-square-inch (psi).Suppose you take a random sample of 15 measurements throughout the day of the psi and find the standard deviation to be 148.Suppose you want to test whether the press is operating correctly.
What are the appropriate null and alternative hypotheses?

A)H₀ : σ² = 120² and H₁ : σ² > 120²
B)H₀ : σ = 120 and H₁ : σ < 120
C)H₀ : σ = 120 and H₁ : σ ≠ 120
D)H₀ : σ² > 120 and H₁ : σ² ≤ 120

Question 47

The Next Questions Are Based On The Following Information:
An alcohol brewery firm claims that the proportion of alcohol in their new drink is at most 10 percent.A random sample of 100 bottles of the drink were selected and found to consist of 9 percent alcohol.
What is the value of test statistic for this sample?

A)2.70
B)-0.85
C)-0.33
D)-1.66

Question 48

The Next Questions Are Based On The Following Information:
A hydraulic press is operating correctly when the standard deviation of the pressure is less than 120 pounds-per-square-inch (psi).Suppose you take a random sample of 15 measurements throughout the day of the psi and find the standard deviation to be 148.Suppose you want to test whether the press is operating correctly.
Suppose you have the following null and alternative hypotheses: H₀ : σ² = 34.5 and H₁ : σ² > 34.5.If you take a random sample of 15 observations from a normally distributed population and find that s² = 48.1,what is the most accurate statement that can be made about the p-value for this test?

A)0)01 < p-value < 0.025
B)0)025 < p-value < 0.05
C)p-value < 0.01
D)0)05 < p-value < 0.10

Question 49

The Next Questions Are Based On The Following Information:
A hydraulic press is operating correctly when the standard deviation of the pressure is less than 120 pounds-per-square-inch (psi).Suppose you take a random sample of 15 measurements throughout the day of the psi and find the standard deviation to be 148.Suppose you want to test whether the press is operating correctly.
A random sample of size 10 is selected from a normal population,where the population standard deviation is unknown.Assume that a two-tailed test at the 0.10 significance level is to be used.For what value of t will the null hypothesis not be rejected?

A)to the left of -1.812 or to the right of 1.812
B)to the left of -1.372 or to the right of 1.372
C)to the left of -1.833 or to the right of 1.833
D)to the left of -1.383 or to the right of 1.383

Question 50

The Next Questions Are Based On The Following Information:
A hydraulic press is operating correctly when the standard deviation of the pressure is less than 120 pounds-per-square-inch (psi).Suppose you take a random sample of 15 measurements throughout the day of the psi and find the standard deviation to be 148.Suppose you want to test whether the press is operating correctly.
Rosanne is the floor manager at Yesbe Beauty Products,who takes care of the face cream section.One of her tasks is to make sure that the face cream mini packs weigh four ounces (4.0)on average.Assume that the standard deviation of the weight of the mini packs is known to be 0.1 ounces.Rosanne tasks one of her employees to choose 25 packs at random and find the average weight.For what values would Rosanne tell the employee to reject the production,if she wanted the probability of a Type I error to be 0.10 or less?

A)Reject the production if the average weight < 3.955.
B)Reject the production if the average weight < 3.975.
C)Reject the production if the average weight < 3.965.
D)Reject the production if the average weight < 3.985.

Question 51

The Next Questions Are Based On The Following Information:
An alcohol brewery firm claims that the proportion of alcohol in their new drink is at most 10 percent.A random sample of 100 bottles of the drink were selected and found to consist of 9 percent alcohol.
What conclusions can be drawn using a level of significance equal to 0.10?

A)Since the p-value equals 0.9965,fail to reject the null hypothesis and conclude that the proportion of alcohol is not greater than 10 percent.
B)Since the p-value equals 0.6293 fail to reject the null hypothesis and conclude that the proportion of alcohol is not greater than 10 percent.
C)Since the p-value equals 0.0485,reject the null hypothesis and conclude that that the proportion of alcohol is not less than 10 percent.
D)Since the p-value equals 0.1977,reject the null hypothesis and conclude that that the proportion of alcohol is less than 10 percent.

Question 52

The Next Questions Are Based On The Following Information:
A professor claims that the average score on a recent exam was 83.Suppose you want to test whether the professor's statement is correct.Assume that the test scores are normally distributed.You ask some people in class how they did,and record the following scores: 82,77,85,76,81,91,70,and 82.
Which of the following is the most accurate statement about the p-value?

A)p-value > 0.10
B)0.01 < p-value < 0.05
C)0.05 < p-value < 0.10
D)p-value < 0.01

Question 53

The Next Questions Are Based On The Following Information:
A hydraulic press is operating correctly when the standard deviation of the pressure is less than 120 pounds-per-square-inch (psi).Suppose you take a random sample of 15 measurements throughout the day of the psi and find the standard deviation to be 148.Suppose you want to test whether the press is operating correctly.
Which of the following is true of the p-value?

A)It is the probability of rejecting the null hypothesis when the null hypothesis is true.
B)It is the smallest significance level at which a null hypothesis can be rejected.
C)It is the probability of rejecting the null hypothesis when the alternative hypothesis is true.
D)It is the extreme value of the test statistic obtained when the alternative hypothesis is true.

Question 54

The Next Questions Are Based On The Following Information:
The state lottery office claims that the average household income of those people playing the lottery is at least $37,000.Assume that the distribution of household income of those people playing the lottery is normally distributed with a standard deviation of $5,756.Suppose that for a sample of 25 households,it is found that the average income was $36,243.
What is the most accurate estimate of the p-value?

A)p-value > 0.10
B)0.01 < p-value < 0.05
C)0.05 < p-value < 0.10
D)p-value < 0.01

Question 55

The Next Questions Are Based On The Following Information:
A hydraulic press is operating correctly when the standard deviation of the pressure is less than 120 pounds-per-square-inch (psi).Suppose you take a random sample of 15 measurements throughout the day of the psi and find the standard deviation to be 148.Suppose you want to test whether the press is operating correctly.
What is the decision rule for this test?

A)Reject H₀ if (n - 1)s / σ₀ >
or <

B)Reject H₀ if (n - 1)s / σ₀ >
C)Reject H₀ if (n - 1)s² /
>

D)Reject H₀ if (n - 1)s / σ₀ >

Question 56

The Next Questions Are Based On The Following Information:
A small community college claims that their average class size is equal to 35 students.This claim is being tested with a level of significance equal to 0.02 using the following sample of class sizes: 42,28,36,47,35,41,33,30,39,and 48.Assume class sizes are normally distributed.
Suppose you have the following null and alternative hypotheses: H₀ : μ = 8.3 and H₁ : μ ≠ 8.3.You take a sample of 30 observations,and find a sample mean of 7.3 with a standard deviation of 3.2.Which of the following is the most accurate statement about the p-value?

A)0)01 < p-value < 0.05
B)0)05 < p-value < 0.10
C)p-value > 0.10
D)p-value < 0.01

Question 57

The Next Questions Are Based On The Following Information:
The state lottery office claims that the average household income of those people playing the lottery is at least $37,000.Assume that the distribution of household income of those people playing the lottery is normally distributed with a standard deviation of $5,756.Suppose that for a sample of 25 households,it is found that the average income was $36,243.
What are the appropriate null and alternative hypotheses?

A)H₀ : μ = $37,000 and H₁ : μ > $37,000
B)H₀ : μ = $37,000 and H₁ : μ ≠ $37,000
C)H₀ : μ = $37,000 and H₁ : μ < $37,000
D)H₀ : μ > $37,000 and H₁ : μ ≤ $37,000

Question 58

The Next Questions Are Based On The Following Information:
A hydraulic press is operating correctly when the standard deviation of the pressure is less than 120 pounds-per-square-inch (psi).Suppose you take a random sample of 15 measurements throughout the day of the psi and find the standard deviation to be 148.Suppose you want to test whether the press is operating correctly.
For a two-tailed test at the 0.05 significance level,what is the rejection region when n is large and the population standard deviation is known?

A)between -1.645 and +1.645
B)between -1.96 and +1.96
C)less than -1.645 or greater than +1.645
D)less than -1.96 and greater than 1.96

Question 59

The Next Questions Are Based On The Following Information:
A professor claims that the average score on a recent exam was 83.Suppose you want to test whether the professor's statement is correct.Assume that the test scores are normally distributed.You ask some people in class how they did,and record the following scores: 82,77,85,76,81,91,70,and 82.
What are the null and alternative hypotheses?

A)H₀ : μ = 83 and H₁ : μ > 83
B)H₀ : μ = 83 and H₁ : μ < 83
C)H₀ : μ = 83 and H₁ : μ ≠ 83
D)H₀ : μ > 83 and H₁ : μ ≤ 83

Question 60

The Next Questions Are Based On The Following Information:
An alcohol brewery firm claims that the proportion of alcohol in their new drink is at most 10 percent.A random sample of 100 bottles of the drink were selected and found to consist of 9 percent alcohol.
What is the p-value for this test?

A)0.9965
B)0.1977
C)0.0485
D)0.6293

Question 61

THE Next Questions Are Based On The Following Information:
A large milling machine produces steel rods to certain specifications.The machine is considered to be running normally if the standard deviation of the diameter of the rods is at most 0.15 millimeters.The line supervisor needs to test the machine is for normal functionality.The quality inspector takes a sample of 25 rods and finds that the sample standard deviation is 0.19.
What are the null and alternative hypotheses for the test?

A)H₀ : σ² > 0.15 and H₁ : σ² ≤ 0.15
B)H₀ : σ ≥ 0.15 and H₁ : σ < 0.15
C)H₀ : σ = 0.0225 and H₁ : σ ≠ 0.0225
D)H₀ : σ² ≤ 0.0225 and H₁ : σ² > 0.0225

Question 62

The larger the population variance,the higher the power of the test.

Question 63

The probability of rejecting the null hypothesis when the null hypothesis is false is known as the power of the test.

Question 64

If a researcher fails to reject the null hypothesis,then the alternative hypothesis should be accepted.

Question 65

The farther the true mean is from the hypothesized mean,the greater is the power of the test,everything else being equal.

Question 66

A null hypothesis is rejected at the 0.025 level,but is not rejected at the 0.01 level.This means that the p-value of the test is between 0.01 and 0.025.

Question 67

The p-value of a test is the probability that the null hypothesis is true.

Question 68

The significance level and the probability of a Type I error are equivalent.

Question 69

Increasing the probability of a Type I error by one percent decreases the probability of a Type II error by one percent.

Question 70

The Next Questions Are Based On The Following Information:
A hydraulic press is operating correctly when the standard deviation of the pressure is less than 120 pounds-per-square-inch (psi).Suppose you take a random sample of 15 measurements throughout the day of the psi and find the standard deviation to be 148.Suppose you want to test whether the press is operating correctly.
What can be concluded by failing to reject the null hypothesis?

A)that the null hypothesis is correct,therefore the alternative hypothesis should be rejected
B)that the alternative hypothesis is correct,therefore the null hypothesis should be rejected
C)that the function of the alternative hypothesis is incorrect
D)that the test procedure is not strong enough to reject the null hypothesis

Question 71

THE Next Questions Are Based On The Following Information:
A large milling machine produces steel rods to certain specifications.The machine is considered to be running normally if the standard deviation of the diameter of the rods is at most 0.15 millimeters.The line supervisor needs to test the machine is for normal functionality.The quality inspector takes a sample of 25 rods and finds that the sample standard deviation is 0.19.
Which of the following statements is the most accurate?

A)Reject null hypothesis at α = 0.025
B)Fail to reject null hypothesis at α ≤ 0.10
C)Reject null hypothesis at α = 0.05
D)Reject null hypothesis at α = 0.01

Question 72

When testing whether a population proportion is zero,a t test can be used only if the sample size is large.

Question 73

If a null hypothesis is rejected against an alternative at the 5% level,then using the same data,it must be rejected against that alternative at the 1% level.

Question 74

If the null hypothesis is H₀ : μ = 100,and you know that
= 105 and
= σ /
= 2.5,then the test statistic value is Z = 2.

Question 75

The probability of rejecting a true null hypothesis is denoted by β.

Question 76

Increasing the significance level of a test increases the probability of a Type II error.

Question 77

The power of a test is inversely related to the probability of a Type II error.

Question 78

The larger the sample size,the greater the power of the test with everything else being equal.

Question 79

It is not possible to determine p-values for the chi-square test for variances.

Question 80

The critical region (or decision rule)of a test,indicates when to reject the alternative hypothesis.