Question 1

A sample of n = 4 scores with SS = 48 has a variance of 16 and an estimated standard error of 2.

Accepted Answer

A) True 
 B)False

Question 2

If other factors are held constant,as the sample size increases,the estimated standard error decreases.

Accepted Answer

A) True 
 B)False

Question 3

With α = .05 and df = 8,the critical values for a two-tailed t test are t = ±2.306.Assuming all other factors are held constant,if the df value were increased to df = 20,what would happen to the critical values for t?

Accepted Answer

A) They would increase (move farther from zero). 
B) They would decrease (move closer to zero). 
C) They would stay the same. 
D) Not enough information to answer 
A) They would increase (move farther from zero). 
B) They would decrease (move closer to zero). 
C) They would stay the same. 
D) Not enough information to answer

Question 4

A sample is selected from a population with μ = 70,and a treatment is administered to the sample.After treatment,the sample mean is M = 74,and Cohen's d is d = 1.00.What is the value of the sample variance?

Accepted Answer

A) s2 = 2 
B) s2 = 4 
C) s2 = 16 
D) It is impossible to determine the sample variance without more information. 
A) s2 = 2 
B) s2 = 4 
C) s2 = 16 
D) It is impossible to determine the sample variance without more information.

Question 5

A sample of n = 25 scores has a mean of M = 40 and a standard deviation of s = 10.What is the estimated standard error for the sample mean?

Accepted Answer

A) 4 
B) 2 
C) (?0v2) 
D) 1 
A) 4 
B) 2 
C) (?0v2) 
D) 1

Question 6

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

Accepted Answer

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

Question 7

A sample of n = 4 scores has SS = 60.What is the variance for this sample?

Accepted Answer

A) 30 
B) 20 
C) 16 
D) 15 
A) 30 
B) 20 
C) 16 
D) 15

Question 8

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

Question 9

In order to estimate a population mean with a confidence interval,you first must estimate a range of values for t.

Accepted Answer

A) True 
 B)False

Question 10

When the population variance or standard deviation is not known,you must use a t statistic instead of a z-score for a hypothesis test.

Accepted Answer

A) True 
 B)False

Question 11

What is the sample variance and the estimated standard error for a sample of n = 9 scores with SS = 72?

Accepted Answer

A) s2 = 9 and sM = 3 
B) s2 = 9 and sM = 1 
C) s2 = 3 and sM = 3 
D) s2 = 3 and sM = 1 
A) s2 = 9 and sM = 3 
B) s2 = 9 and sM = 1 
C) s2 = 3 and sM = 3 
D) s2 = 3 and sM = 1

Question 12

If other factors are held constant,which set of sample characteristics is most likely to reject a null hypothesis stating that  = 80?

Accepted Answer

A) M = 85 and small sample variance 
B) M = 85 and large sample variance 
C) M = 90 and small sample variance 
D) M = 90 and large sample variance 
A) M = 85 and small sample variance 
B) M = 85 and large sample variance 
C) M = 90 and small sample variance 
D) M = 90 and large sample variance

Question 13

For a two-tailed hypothesis test with α = .05 and a sample of n = 25 scores,the boundaries for the critical region are t = ±2.060.

Accepted Answer

A) True 
 B)False

Question 14

Which of the following is the correct way to report the results of a hypothesis test and a measure of effect size using a t statistic?

Accepted Answer

A) t(19)= 2.30,r2 = 0.42,p 2 = 0.42, 
C) r2 = 0.42,t(19)= 2.30 ,p 2 = 0.42 
A) t(19)= 2.30,r2 = 0.42,p 2 = 0.42, 
C) r2 = 0.42,t(19)= 2.30 ,p 2 = 0.42

Question 15

A sample is selected from a population with μ = 46,and a treatment is administered to the sample.After treatment,the sample mean is M = 48 with a sample variance of s2 = 16.Based on this information,what is the value of Cohen's d?

Accepted Answer

A) d = 0.125 
B) d = 0.25 
C) d = 0.50 
D) Cohen's d cannot be computed without knowing the sample size. 
A) d = 0.125 
B) d = 0.25 
C) d = 0.50 
D) Cohen's d cannot be computed without knowing the sample size.

Question 16

Which combination of factors would definitely increase the width of a confidence interval?

Accepted Answer

A) Increase the sample mean and increase the size of the sample 
B) Decrease the sample mean and increase the size of the sample 
C) Increase the sample mean and increase the percentage of confidence 
D) Decrease the sample mean and decrease the percentage of confidence 
A) Increase the sample mean and increase the size of the sample 
B) Decrease the sample mean and increase the size of the sample 
C) Increase the sample mean and increase the percentage of confidence 
D) Decrease the sample mean and decrease the percentage of confidence

Question 17

For a hypothesis test using a t statistic,the boundaries for the critical region will change if the sample size is changed.

Accepted Answer

A) True 
 B)False

Question 18

As sample size increases,the critical region boundaries for a two-tailed test with  = .05 will move closer to zero.

Accepted Answer

A) True 
 B)False

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. 
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

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

A sample of n = 4 scores with SS = 48 has a variance of 16 and an estimated standard error of 2.

If other factors are held constant,as the sample size increases,the estimated standard error decreases.

With α = .05 and df = 8,the critical values for a two-tailed t test are t = ±2.306.Assuming all other factors are held constant,if the df value were increased to df = 20,what would happen to the critical values for t?

A sample is selected from a population with μ = 70,and a treatment is administered to the sample.After treatment,the sample mean is M = 74,and Cohen's d is d = 1.00.What is the value of the sample variance?

A sample of n = 25 scores has a mean of M = 40 and a standard deviation of s = 10.What is the estimated standard error for the sample mean?

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

A sample of n = 4 scores has SS = 60.What is the variance for this sample?

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?

In order to estimate a population mean with a confidence interval,you first must estimate a range of values for t.

When the population variance or standard deviation is not known,you must use a t statistic instead of a z-score for a hypothesis test.

What is the sample variance and the estimated standard error for a sample of n = 9 scores with SS = 72?

If other factors are held constant,which set of sample characteristics is most likely to reject a null hypothesis stating that  = 80?

For a two-tailed hypothesis test with α = .05 and a sample of n = 25 scores,the boundaries for the critical region are t = ±2.060.

Which of the following is the correct way to report the results of a hypothesis test and a measure of effect size using a t statistic?

A sample is selected from a population with μ = 46,and a treatment is administered to the sample.After treatment,the sample mean is M = 48 with a sample variance of s² = 16.Based on this information,what is the value of Cohen's d?

Which combination of factors would definitely increase the width of a confidence interval?

For a hypothesis test using a t statistic,the boundaries for the critical region will change if the sample size is changed.

As sample size increases,the critical region boundaries for a two-tailed test with  = .05 will move closer to zero.

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?

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?

Introduction to Statistics

Frequency Distributions

Measures of Central Tendency

Measures of Variability

Z-Scores

Probability

Probability and Samples:

Introduction to Hypothesis Testing

The T Test for Two Independent Samples

The T Test for Two Related Samples

Introduction to Analysis of Variance

Repeated-Measures and Two-Factor Anova

Correlation and Regression

Chi-Square Tests

Filters

Exam 9: Introduction to the T Statistic

A sample of n = 4 scores with SS = 48 has a variance of 16 and an estimated standard error of 2.

If other factors are held constant,as the sample size increases,the estimated standard error decreases.

With α = .05 and df = 8,the critical values for a two-tailed t test are t = ±2.306.Assuming all other factors are held constant,if the df value were increased to df = 20,what would happen to the critical values for t?

A sample is selected from a population with μ = 70,and a treatment is administered to the sample.After treatment,the sample mean is M = 74,and Cohen's d is d = 1.00.What is the value of the sample variance?

A sample of n = 25 scores has a mean of M = 40 and a standard deviation of s = 10.What is the estimated standard error for the sample mean?

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

A sample of n = 4 scores has SS = 60.What is the variance for this sample?

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?

In order to estimate a population mean with a confidence interval,you first must estimate a range of values for t.

When the population variance or standard deviation is not known,you must use a t statistic instead of a z-score for a hypothesis test.

What is the sample variance and the estimated standard error for a sample of n = 9 scores with SS = 72?

If other factors are held constant,which set of sample characteristics is most likely to reject a null hypothesis stating that  = 80?

For a two-tailed hypothesis test with α = .05 and a sample of n = 25 scores,the boundaries for the critical region are t = ±2.060.

Which of the following is the correct way to report the results of a hypothesis test and a measure of effect size using a t statistic?

A sample is selected from a population with μ = 46,and a treatment is administered to the sample.After treatment,the sample mean is M = 48 with a sample variance of s2 = 16.Based on this information,what is the value of Cohen's d?

Which combination of factors would definitely increase the width of a confidence interval?

For a hypothesis test using a t statistic,the boundaries for the critical region will change if the sample size is changed.

As sample size increases,the critical region boundaries for a two-tailed test with  = .05 will move closer to zero.

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?

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?

Introduction to Statistics

Frequency Distributions

Measures of Central Tendency

Measures of Variability

Z-Scores

Probability

Probability and Samples:

Introduction to Hypothesis Testing

The T Test for Two Independent Samples

The T Test for Two Related Samples

Introduction to Analysis of Variance

Repeated-Measures and Two-Factor Anova

Correlation and Regression

Chi-Square Tests

Filters

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

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?

A sample is selected from a population with μ = 46,and a treatment is administered to the sample.After treatment,the sample mean is M = 48 with a sample variance of s² = 16.Based on this information,what is the value of Cohen's d?