Question 1

Assume that the average person in America weighs 150 pounds ($\mu$).You want to determine whether college students weigh less than the average American.Following are the weights collected on a sample of college students: 120,105,166,170,145,149,135,115,168,138.

Accepted Answer

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Question 2

Which of the following is not an assumption of the t-test?
A)The data should be ordinal or nominal.
B)The population distribution of scores should be symmetrical.
C)The population mean ($\mu$)is known,but the population standard deviation ($\sigma$)is not known.
D)The sample size is typically less than 30.

Accepted Answer

The t-test assumes that the data is interval or ratio, not ordinal or nominal.

Question 3

If a researcher reported for a two-tailed single-sample t-test that t(13)= 1.46,then
A)p < .02.
B)p < .05.
C)p < .01.
D)the results is not significant.

Accepted Answer

The t-value of 1.46 with 13 degrees of freedom is not large enough to reach significance at the common alpha levels (0.05, 0.02, or 0.01) for a two-tailed test.

Question 4

A researcher in interested in whether students who attend private elementary schools do any better on a standard test of intelligence than the general population of elementary school children.A random sample of 75 students at a private elementary school is tested and has a mean intelligence test score of 103.5.The average for the general population of elementary school children is 100 ($\sigma$ = 15).

Accepted Answer

The answer of A researcher in interested in whether students...

Question 5

Chi-square is calculated by summing the[(_____ -_____)² divided by _____]. A)observed; expected; observed B)expected; observed; observed C)observed; expected; expected D)observed; observed; expected

Accepted Answer

The chi-square formula involves comparing the observed frequencies to the expected frequencies. Therefore, the first term in the formula is based on observed values, while the second term involves expected values. The correct formula for chi-square is (observed - expected)^2 / expected, which aligns with answer choice C where observed is in the numerator and expected is in the denominator.

Question 6

What is a t test,when is it used,and what does it tell us?

Accepted Answer

The answer of What is a t test,when is it...

Question 7

Nonparametric is to parametric as _____ is to _____. A)t-test; z-test B)z-test; t-test C)$\chi$²-test; t-test D)t-test; $\chi$²-test

Accepted Answer

The answer of Nonparametric is to parametric as _____ is...

Question 8

How does sample size affect the t_cv?

Accepted Answer

The answer of How does sample size affect the t_cv?...

Question 9

What is a z test,when is it used,and what does it tell us?

Accepted Answer

The answer of What is a z test,when is it...

Question 10

Rich performed a two-tailed test for an experiment in which n=15.He could not find his t critical values table but he remembered the t_cv at df = 20.He decided to compare his t_obt to this t_cv.Is he more likely to make a Type I or a Type II error in this situation?

Accepted Answer

The answer of Rich performed a two-tailed test for an...

Question 11

What is the sampling distribution and how is it related to the standard error of the mean?

Accepted Answer

The answer of What is the sampling distribution and how...

Question 12

Given: For one section of the SAT: $\mu$= 500 and $\sigma$ = 100.The SAT was given to a sample of n=35 and the mean SAT for this sample was 536.Calculate the z-test for this sample mean.Does this sample differ significantly from the population for a two-tailed test?

Accepted Answer

The answer of Given: For one section of the SAT:...

Question 13

What are the assumptions of the z test?

Accepted Answer

The answer of What are the assumptions of the z...

Question 14

Explain why  decreases as the size of the samples in the sampling distribution increase.Your answer should include an explanation based on the formula for  and an explanation of why this formula makes sense (in other words,why would increasing the size of each sample in the sampling distribution cause  to decrease?

Accepted Answer

The answer of Explain why  decreases as the size...

Question 15

Rich performed a two-tailed test for an experiment in which n=20.He could not find his t critical values table but he remembered the t_cv at df = 15.He decided to compare his t_obt to this t_cv.Is he more likely to make a Type I or a Type II error in this situation?

Accepted Answer

The answer of Rich performed a two-tailed test for an...

Question 16

Which of the following is not an assumption of the $\chi$²-test? A)It is a nonparametric test. B)It is appropriate only for ordinal data. C)The frequency in each cell should be at least 5. D)The sample should be randomly selected.

Accepted Answer

The F1F1F1S1F1F1F10²-test is appropriate for nominal data, not just ordinal data. Therefore, option B is not an assumption of the test. The other options, A, C, and D, are all assumptions of the test.

Question 17

If a researcher reported for a one-tailed single-sample t-test that t(10)= 1.96,then
A)p < .02.
B)p < .05.
C)p < .01.
D)p < .001.

Accepted Answer

The critical value for a one-tailed t-test with 10 degrees of freedom at p < .05 is 1.812. Since the obtained t-value (1.96) exceeds the critical value, the result is statistically significant at p < .05. Since it is a one-tailed test, the p-value is not split into two halves, so we do not need to divide the alpha level by 2. Therefore, the correct answer is B.

Question 18

If a researcher reported for a two-tailed single-sample t-test that t(10)= 2.25,then
A)p < .02.
B)p < .05.
C)p < .01.
D)p < .001.

Accepted Answer

The appropriate significance level depends on the specific research question and context, but under standard conventions, a p-value of less than .05 is typically considered statistically significant. Since this is a two-tailed test, the appropriate level of significance is divided by two (i.e., .05/2 = .025). Looking up the critical value for a t-distribution with 10 degrees of freedom at .025 level of significance yields 2.306. Since our calculated t-value (2.25) falls within the range of values that would be considered significant, we reject the null hypothesis and conclude that there is evidence for a true difference between the sample mean and the population mean.

Question 19

How does a t test differ from a z test in terms of when it is used,how it is calculated,and how we determine significance?

Accepted Answer

The answer of How does a t test differ from...

Question 20

When comparing a sample to a population,if you know $\mu$ but not $\sigma$ and have a sample size smaller than 30,you should conduct a _____ test. A)t B)z C)$\chi$² D)phi

Accepted Answer

Since the population standard deviation is unknown and the sample size is smaller than 30, a t-test should be conducted.

Quiz 8: Introduction to Inferential Statistics

Assume that the average person in America weighs 150 pounds ( $\mu$ ).You want to determine whether college students weigh less than the average American.Following are the weights collected on a sample of college students: 120,105,166,170,145,149,135,115,168,138.

Which of the following is not an assumption of the t-test?

If a researcher reported for a two-tailed single-sample t-test that t(13) = 1.46,then

Chi-square is calculated by summing the[(___ -_) ² divided by ___].

What is a t test,when is it used,and what does it tell us?

Nonparametric is to parametric as _ is to _.

How does sample size affect the t_cv?

What is a z test,when is it used,and what does it tell us?

Rich performed a two-tailed test for an experiment in which n=15.He could not find his t critical values table but he remembered the t_cv at df = 20.He decided to compare his t_obt to this t_cv.Is he more likely to make a Type I or a Type II error in this situation?

What is the sampling distribution and how is it related to the standard error of the mean?

Given: For one section of the SAT: $\mu$ = 500 and $\sigma$ = 100.The SAT was given to a sample of n=35 and the mean SAT for this sample was 536.Calculate the z-test for this sample mean.Does this sample differ significantly from the population for a two-tailed test?

What are the assumptions of the z test?

Rich performed a two-tailed test for an experiment in which n=20.He could not find his t critical values table but he remembered the t_cv at df = 15.He decided to compare his t_obt to this t_cv.Is he more likely to make a Type I or a Type II error in this situation?

Which of the following is not an assumption of the $\chi$ ²-test?

If a researcher reported for a one-tailed single-sample t-test that t(10) = 1.96,then

If a researcher reported for a two-tailed single-sample t-test that t(10) = 2.25,then

How does a t test differ from a z test in terms of when it is used,how it is calculated,and how we determine significance?

When comparing a sample to a population,if you know $\mu$ but not $\sigma$ and have a sample size smaller than 30,you should conduct a _____ test.

Quiz 8: Introduction to Inferential Statistics

Assume that the average person in America weighs 150 pounds ( μ\muμ ).You want to determine whether college students weigh less than the average American.Following are the weights collected on a sample of college students: 120,105,166,170,145,149,135,115,168,138.

Which of the following is not an assumption of the t-test?

If a researcher reported for a two-tailed single-sample t-test that t(13) = 1.46,then

Chi-square is calculated by summing the[(_____ -_____) 2 divided by _____].

What is a t test,when is it used,and what does it tell us?

Nonparametric is to parametric as _____ is to _____.

How does sample size affect the tcv?

What is a z test,when is it used,and what does it tell us?

Rich performed a two-tailed test for an experiment in which n=15.He could not find his t critical values table but he remembered the tcv at df = 20.He decided to compare his tobt to this tcv.Is he more likely to make a Type I or a Type II error in this situation?

What is the sampling distribution and how is it related to the standard error of the mean?

Given: For one section of the SAT: μ\muμ = 500 and σ\sigmaσ = 100.The SAT was given to a sample of n=35 and the mean SAT for this sample was 536.Calculate the z-test for this sample mean.Does this sample differ significantly from the population for a two-tailed test?

What are the assumptions of the z test?

Rich performed a two-tailed test for an experiment in which n=20.He could not find his t critical values table but he remembered the tcv at df = 15.He decided to compare his tobt to this tcv.Is he more likely to make a Type I or a Type II error in this situation?

Which of the following is not an assumption of the χ\chiχ 2-test?

If a researcher reported for a one-tailed single-sample t-test that t(10) = 1.96,then

If a researcher reported for a two-tailed single-sample t-test that t(10) = 2.25,then

How does a t test differ from a z test in terms of when it is used,how it is calculated,and how we determine significance?

When comparing a sample to a population,if you know μ\muμ but not σ\sigmaσ and have a sample size smaller than 30,you should conduct a _____ test.

Assume that the average person in America weighs 150 pounds ( $\mu$ ).You want to determine whether college students weigh less than the average American.Following are the weights collected on a sample of college students: 120,105,166,170,145,149,135,115,168,138.

Chi-square is calculated by summing the[(___ -_) ² divided by ___].

Nonparametric is to parametric as _ is to _.

How does sample size affect the t_cv?

Rich performed a two-tailed test for an experiment in which n=15.He could not find his t critical values table but he remembered the t_cv at df = 20.He decided to compare his t_obt to this t_cv.Is he more likely to make a Type I or a Type II error in this situation?

Given: For one section of the SAT: $\mu$ = 500 and $\sigma$ = 100.The SAT was given to a sample of n=35 and the mean SAT for this sample was 536.Calculate the z-test for this sample mean.Does this sample differ significantly from the population for a two-tailed test?

Rich performed a two-tailed test for an experiment in which n=20.He could not find his t critical values table but he remembered the t_cv at df = 15.He decided to compare his t_obt to this t_cv.Is he more likely to make a Type I or a Type II error in this situation?

Which of the following is not an assumption of the $\chi$ ²-test?

When comparing a sample to a population,if you know $\mu$ but not $\sigma$ and have a sample size smaller than 30,you should conduct a _____ test.