Question 1

If the null hypothesis states that µ = 70 and a researcher obtains a sample with M = 73 and s² = 9,then Cohen's d = 0.33.

Accepted Answer

A) True 
 B)False

Question 2

A sample of n = 16 scores produces a t statistic of t = 2.00.If the sample is used to measure effect size with r²,what value will be obtained for r²?

Accepted Answer

A)  r² = 2/20
B)  r² = 4/20
C)  r² = 2/19
D)  r² = 4/19

Question 3

If other factors are held constant,as the sample variance increases,the estimated standard error also increases.

Accepted Answer

A) True 
 B)False

Question 4

How does sample variance influence the estimated standard error and measures of effect size such as r² and Cohen's d?

Accepted Answer

A)  Larger variance increases both the standard error and measures of effect size.
B)  Larger variance increases the standard error but decreases measures of effect size.
C)  Larger variance decreases the standard error but increases measures of effect size.
D)  Larger variance decreases both the standard error and measures of effect size.

Question 5

Which of the following is a fundamental difference between the t statistic and a z-score?

Accepted Answer

A)  The t statistic uses the sample mean in place of the population mean.
B)  The t statistic uses the sample variance in place of the population variance.
C)  The t statistic computes the standard error by dividing the standard deviation by n - 1 instead of dividing by n.
D)  All of these are differences between t and z.

Question 6

A sample of n = 16 scores with a sample variance of s² = 64 has an estimated standard error of 4 points.

Accepted Answer

A) True 
 B)False

Question 7

With α = .05,what is the critical t value for a one-tailed test with n = 15?

Accepted Answer

A)  t = 1.761
B)  t = 1.753
C)  t = 2.145
D)  t = 2.131

Question 8

If other factors are held constant,which set of sample characteristics is most likely to produce a significant t statistic?

Accepted Answer

A)  n = 25 with s2 = 100
B)  n = 25 with s2 = 400
C)  n = 100 with s2 = 100
D)  n = 100 with s2 = 400

Question 9

In general,the larger the value of the sample variance,the greater the likelihood of rejecting the null hypothesis.

Accepted Answer

A) True 
 B)False

Question 10

A sample of n = 4 scores is selected from a population with an unknown mean.The sample has a mean of M = 40 and a variance of s² = 16.Which of the following is the correct 90% confidence interval for μ?

Accepted Answer

A)  μ = 40 ± 2.353(4) 
B)  μ = 40 ± 1.638(4) 
C)  μ = 40 ± 2.353(2) 
D)  μ = 40 ± 1.638(2)

Question 11

Why are t statistics more variable than z-scores?

Accepted Answer

A)  The extra variability is caused by variations in the sample mean.
B)  The extra variability is caused by variations in the sample variance.
C)  The extra variability is caused by variations in the df value.
D)  None of the other options explains the extra variability for t statistics.

Question 12

Compared to a z-score,a hypothesis test with a t statistic requires more information from the sample.

Accepted Answer

A) True 
 B)False

Question 13

As the sample size is increased,the distribution of t statistics becomes flatter and more spread out.

Accepted Answer

A) True 
 B)False

Question 14

A sample of n = 9 scores has a variance of s² = 36.What is the estimated standard error for the sample mean?

Accepted Answer

A)  1
B)  2
C)  4
D)  16

Question 15

If other factors are held constant,how does sample size influence the likelihood of rejecting the null hypothesis and measures of effect size such as r² and Cohen's d?

Accepted Answer

A)  A larger sample increases both the likelihood and measures of effect size.
B)  A larger sample increases the likelihood but has little influence on measures of effect size.
C)  A larger sample decreases the likelihood but has little influence on measures of effect size.
D)  A larger sample decreases both the likelihood and measures of effect size.

Question 16

Which of the following would have no effect on the width of a confidence interval?

Accepted Answer

A)  Increase the sample mean
B)  Increase the size of the sample
C)  Increase the percentage of confidence
D)  Increase the sample variance

Question 17

A researcher conducts a hypothesis test using a sample from an unknown population.If the t statistic has df = 30,how many individuals were in the sample?

Accepted Answer

A)  n = 29
B)  n = 30
C)  n = 31
D)  Cannot be determined from the information given

Question 18

A researcher selects a sample from a population with μ = 30 and uses the sample to evaluate the effect of a treatment.After treatment,the sample has a mean of M = 32 and a variance of s² = 6.If Cohen's d is used to measure the size of the treatment effect,which of the following would have no effect on the value of Cohen's d?

Accepted Answer

A)  Increase the sample size
B)  Increase the sample mean
C)  Increase the sample variance
D)  All of the other options will influence the value of Cohen's d.

Question 19

A sample has a mean of M = 39.5 and a standard deviation of s = 4.3,and produces a t statistic of t = 2.14.For a two-tailed hypothesis test with α = .05,what is the correct statistical decision for this sample?

Accepted Answer

A)  The researcher can reject the null hypothesis with α = .05 but not with α = .01.
B)  The researcher can reject the null hypothesis with either α = .05 or α = .01.
C)  The researcher must fail to reject the null hypothesis with either α = .05 or α = .01.
D)  It is impossible to make a decision about H0 without more information.

Question 20

Two samples from the same population both have n = 10 scores with M = 45.If the t statistic is computed for each sample,then what is the relationship between the two t values?

Accepted Answer

A)  The two t statistics will be identical.
B)  The sample with the larger variance will produce the larger t statistic.
C)  The sample with the smaller variance will produce the larger t statistic.
D)  There is no way to predict the relationship between the two t statistics.

Exam 9: Introduction to the t Statistic

Two samples from the same population both have n = 10 scores with M = 45.If the t statistic is computed for each sample,then what is the relationship between the two t values?

Correct Answer
verified

In general,the larger the value of the sample variance,the greater the likelihood of rejecting the null hypothesis.

Correct Answer
verified

With α = .05,what is the critical t value for a one-tailed test with n = 15?

Correct Answer
verified

Which of the following would have no effect on the width of a confidence interval?

Correct Answer
verified

As the sample size is increased,the distribution of t statistics becomes flatter and more spread out.

Correct Answer
verified

Why are t statistics more variable than z-scores?

Correct Answer
verified

Compared to a z-score,a hypothesis test with a t statistic requires more information from the sample.

Correct Answer
verified

A sample of n = 16 scores with a sample variance of s² = 64 has an estimated standard error of 4 points.

Correct Answer
verified

A sample of n = 4 scores is selected from a population with an unknown mean.The sample has a mean of M = 40 and a variance of s² = 16.Which of the following is the correct 90% confidence interval for μ?

Correct Answer
verified

If other factors are held constant,how does sample size influence the likelihood of rejecting the null hypothesis and measures of effect size such as r² and Cohen's d?

Correct Answer
verified

If other factors are held constant,which set of sample characteristics is most likely to produce a significant t statistic?

Correct Answer
verified

Which of the following is a fundamental difference between the t statistic and a z-score?

Correct Answer
verified

If the null hypothesis states that µ = 70 and a researcher obtains a sample with M = 73 and s² = 9,then Cohen's d = 0.33.

Correct Answer
verified

How does sample variance influence the estimated standard error and measures of effect size such as r² and Cohen's d?

Correct Answer
verified

A sample has a mean of M = 39.5 and a standard deviation of s = 4.3,and produces a t statistic of t = 2.14.For a two-tailed hypothesis test with α = .05,what is the correct statistical decision for this sample?

Correct Answer
verified

If other factors are held constant,as the sample variance increases,the estimated standard error also increases.

Correct Answer
verified

Correct Answer
verified

A sample of n = 9 scores has a variance of s² = 36.What is the estimated standard error for the sample mean?

Correct Answer
verified

A sample of n = 16 scores produces a t statistic of t = 2.00.If the sample is used to measure effect size with r²,what value will be obtained for r²?

Correct Answer
verified

A researcher conducts a hypothesis test using a sample from an unknown population.If the t statistic has df = 30,how many individuals were in the sample?

Correct Answer
verified

Exam 9: Introduction to the t Statistic

Two samples from the same population both have n = 10 scores with M = 45.If the t statistic is computed for each sample,then what is the relationship between the two t values?

Correct AnswerverifiedShow Answer

In general,the larger the value of the sample variance,the greater the likelihood of rejecting the null hypothesis.

Correct AnswerverifiedShow Answer

With α = .05,what is the critical t value for a one-tailed test with n = 15?

Correct AnswerverifiedShow Answer

Which of the following would have no effect on the width of a confidence interval?

Correct AnswerverifiedShow Answer

As the sample size is increased,the distribution of t statistics becomes flatter and more spread out.

Correct AnswerverifiedShow Answer

Why are t statistics more variable than z-scores?

Correct AnswerverifiedShow Answer

Compared to a z-score,a hypothesis test with a t statistic requires more information from the sample.

Correct AnswerverifiedShow Answer

A sample of n = 16 scores with a sample variance of s² = 64 has an estimated standard error of 4 points.

Correct AnswerverifiedShow Answer

A sample of n = 4 scores is selected from a population with an unknown mean.The sample has a mean of M = 40 and a variance of s² = 16.Which of the following is the correct 90% confidence interval for μ?

Correct AnswerverifiedShow Answer

If other factors are held constant,how does sample size influence the likelihood of rejecting the null hypothesis and measures of effect size such as r² and Cohen's d?

Correct AnswerverifiedShow Answer

If other factors are held constant,which set of sample characteristics is most likely to produce a significant t statistic?

Correct AnswerverifiedShow Answer

Which of the following is a fundamental difference between the t statistic and a z-score?

Correct AnswerverifiedShow Answer

If the null hypothesis states that µ = 70 and a researcher obtains a sample with M = 73 and s² = 9,then Cohen's d = 0.33.

Correct AnswerverifiedShow Answer

How does sample variance influence the estimated standard error and measures of effect size such as r² and Cohen's d?

Correct AnswerverifiedShow Answer

A sample has a mean of M = 39.5 and a standard deviation of s = 4.3,and produces a t statistic of t = 2.14.For a two-tailed hypothesis test with α = .05,what is the correct statistical decision for this sample?

Correct AnswerverifiedShow Answer

If other factors are held constant,as the sample variance increases,the estimated standard error also increases.

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

A sample of n = 9 scores has a variance of s² = 36.What is the estimated standard error for the sample mean?

Correct AnswerverifiedShow Answer

A sample of n = 16 scores produces a t statistic of t = 2.00.If the sample is used to measure effect size with r²,what value will be obtained for r²?

Correct AnswerverifiedShow Answer

A researcher conducts a hypothesis test using a sample from an unknown population.If the t statistic has df = 30,how many individuals were in the sample?

Correct AnswerverifiedShow Answer

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