Deck 8: Hypothesis Testing

Question 1

The following MINITAB output presents a 95% confidence interval. )

Answer 1

C

Question 2

A population has a standard deviation How large a sample must be drawn so that a 98% confidence interval for will have a margin of error equal to 4.2 ?

A) 226
B) 126
C) 11
D) 5

Answer 2

126

Question 3

The following MINITAB output presents a 95% confidence interval. )

Answer 3

A

Question 4

The three confidence intervals below were constructed from the same sample. )

Question 5

Assume the population standard deviation is and that the population is approximat normal. Construct a 95 % confidence interval for the mean price for all the TI-89's being sold over the internet.

A) (134.0,170.6)
B) (145.6,159.1)
C) (145.5,159.2)
D) (97.5,207.2)

Question 6

Find the level of the confidence interval that has the given critical value.1.53

A)93.7%
B)87.40%
C)12.6%
D)6.3%

Question 7

Find the critical value needed to construct a(n) 80% confidence interval.

A) 0.84
B) 1.08
C) 1.28
D) 2.10

Question 8

A sample of 132 tobacco smokers who recently completed a new smoking-cessationprogram were asked to rate the effectiveness of the program on a scale of 1 to 10

Question 9

The following MINITAB output presents a 95% confidence interval. )

Question 10

A sample of size n=11 has a sample mean and sample standard deviation s=2.4 . Construct a 95 % confidence interval for the population mean

A) (14.0,17.2)
B) (15.1,16.1)
C) (14.3,16.9)
D) (14.6,16.6)

Question 11

A sample of 37 light bulbs had a mean lifetime of 584 hours. A 95 % confidence interval for the population mean was
Which one of the following statements is the correct interpretation of the results?

A) None of these are true.
B) 95 % of the light bulbs in the sample had lifetimes between 579.2 hours and 588.8 hours
C) The probability that the population mean is between 579.2 hours and 588.8 hours is 0.95 .
D) We are 95 % confident that the mean lifetime of all the bulbs in the population is between 579.2 hours and 588.8 hours.

Question 12

Question 13

Find the critical value needed to construct a(n) 99.5% confidence interval.

A) 2.81
B) 2.53
C) 3.71
D) 2.58

Question 14

Find the critical value needed to construct a confidence interval of the given level with the given sample size.
Level 95 % , sample size 11

A) 1.812
B) 1.960
C) 2.228
D) 2.201

Question 15

A sample of size n=15 is drawn from an approximately normal population whose standard deviation is The sample mean is Construct a 90 % confidence interval for

A) (30.28,51.32)
B) (40.80,43.14)
C) (39.80,41.80)
D) 38.46,43.14

Question 16

A sample of size n=22 is drawn from a normal population. Find the critical value needed to construct a 98 % confidence interval.

A) 2.326
B) 2.508
C) 2.189
D) 2.518

Question 17

A random sample of 9 TI-89 Titanium calculators being sold over the internet had the following

Question 18

The following MINITAB output presents a 95% confidence interval. )

Question 19

A sample of size n=50 is drawn from a population whose standard deviation is Find the margin of error for a 90 % confidence interval for

A) 3.37
B) 0.80
C) 0.89
D) 2.05

Question 20

A simple random sample of kitchen toasters is to be taken to determine the mean operational lifetime in hours. Assume that the lifetimes are normally distributed with population standard deviation
Find the sample size needed so that a 95 % confidence interval for the mean lifetime will have a margin of error of 4 .

A) 2
B) 385
C) 189
D) 14

Question 21

The following MINITAB output presents a confidence interval for a population mean. )

Question 22

The following display from a TI-84 Plus calculator presents a 95% confidence interval. )

Question 23

Find the margin of error for the given confidence level and values of x and n . x=79, n=187 , confidence level 98%

A) 0.08402
B) 0.4225
C) 0.03612
D) 0.5775

Question 24

The following MINITAB output presents a confidence interval for a proportion. )

Question 25

A researcher wants to construct a 98% confidence interval for the proportion ofelementary school students in Seward County who receive free or reduced-price schoollunches. A state-wide survey indicates that the proportion is 0.45. Using this estimate,what sample size is needed so that the confidence interval will have a margin of error of0.08?

A)210
B)8
C)17
D)149

Question 26

Twenty-three concrete blocks were sampled and tested for crushing strength in order toestimate the proportion that were sufficiently strong for a certain application. Eighteen ofthe 23 blocks were sufficiently strong. Use the small-sample method to construct a 95%confidence interval for the proportion of blocks that are sufficiently strong.

A)(0.575, 0.906)
B)(0.614, 0.951)
C)(0.562, 0.920)
D)(0.602, 0.879)

Question 27

The following display from a TI-84 Plus calculator presents a 99% confidence interval for a

Question 28

In a survey of 447 registered voters, 157 of them wished to see Mayor Waffleskate loseher next election. The Waffleskate campaign claims that no more than 27% of registeredvoters wish to see her defeated. Does the 98% confidence interval for the proportionsupport this claim? (Hint: you should first construct the 98% confidence interval for theproportion of registered voters who whish to see Waffleskate defeated.)(0.299, 0.404)

A)The reasonableness of the claim cannot be determined.
B)No
C)Yes

Question 29

Six measurements were made of the magnesium ion concentration (in parts per million,)

Question 30

Find the point estimate for the given values of x and n .
x=104, n=202

A) 104
B) 0.4851
C) 0.03516
D) 0.5149

Question 31

Find the standard error for the given values of x and n .
x=75, n=182

A) 0.03649
B) 75
C) 0.5879
D) 0.4121

Question 32

A researcher wants to construct a 98% confidence interval for the proportion ofelementary school students in Seward County who receive free or reduced-price schoollunches. What sample size is needed so that the confidence interval will have a margin oferror of 0.09?

A)119
B)7
C)167
D)16

Question 33

Boxes of raisins are labeled as containing 22 ounces. )

Question 34

Use the given data to construct a confidence interval of the requested level.
x=114, n=228 , confidence level 90%

A) (0.446,0.554)
B) (0.410,0.590)
C) (0.467,0.533)
D) (0.458,0.542)

Question 35

In a survey of 314 registered voters, 156 of them wished to see Mayor Waffleskate loseher next election. Construct a 95% confidence interval for the proportion of registeredvoter who want to see Mayor Waffleskate defeated.

A)0.450, 0.543)
B)(0.469, 0.525)
C)(0.441, 0.552)
D)(0.388, 0.605)

Question 36

The following MINITAB output presents a confidence interval for a population mean. )

Question 37

In a survey of 302 registered voters, 167 of them wished to see Mayor Waffleskate loseher next election. Find a point estimate for the proportion of registered voters who wishto see Mayor Waffleskate defeated.

A)0.02861
B)0.5530
C)0.4470
D)167

Question 38

Six measurements were made of the magnesium ion concentration (in parts per million,)

Question 39

The following display from a TI-84 Plus calculator presents a 99% confidence interval for a _ and

Question 40

The following MINITAB output presents a confidence interval for a population mean. )

Question 41

The following MINITAB output presents a confidence interval for a proportion. )

Question 42

Construct a 95% confidence interval for the population standard deviation if a sample of size 18 has standard deviation s=20 .

A) (15.70,28.00)
B) (14.69,28.74)
C) (15.01,29.98)
D) (15.11,29.58)

Question 43

There are no testbank questions for this section.

Question 44

Find the critical values for a 95% confidence interval using the chi-square distributionwith 14 degrees of freedom.

A)5.009, 24.736
B)5.892, 22.362
C)6.571, 23.685
D)5.629, 26.119

Question 45

Scores on the math SAT are normally distributed. A sample of 23 SAT scores had a standard deviation s=79 . Construct a 95 % confidence interval for the population standard deviation

A) (63.62,105.49)
B) (60.05,108.38)
C) (61.10,111.81)
D) (61.40,110.82)

Question 46

Following are the heights in inches of 12 two-year-old apple trees. )