Question 1

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 2

For a two-tailed test with α = .05 and a sample of n = 16, the boundaries for the critical region are t = ±2.120.

Accepted Answer

A) True 
 B)False

Question 3

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 4

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

Accepted Answer

A) True 
 B)False

Question 5

A researcher conducts a hypothesis test using a sample of n = 40 from an unknown population.What is the df value for the t statistic?

Accepted Answer

A) 39 
B) 40 
C) 41 
D) cannot be determined from the information given 
A) 39 
B) 40 
C) 41 
D) cannot be determined from the information given

Question 6

If two samples are selected from the same population, under what circumstances will the two samples have exactly the same t statistic?

Accepted Answer

A) If the samples are the same size and have the same variance. 
B) If the samples are the same size and have the same mean. 
C) If the samples have the same mean and the same variance. 
D) If the samples are the same size and have the same mean and have the same variance. 
A) If the samples are the same size and have the same variance. 
B) If the samples are the same size and have the same mean. 
C) If the samples have the same mean and the same variance. 
D) If the samples are the same size and have the same mean and have the same variance.

Question 7

A sample of n = 25 scores produces a t statistic of t = -2.062.If the researcher is using a two-tailed test, then which of the following is the correct statistical decision?

Accepted Answer

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

Question 8

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. 
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 9

When n is small (less than 30), how does the shape of the t distribution compare to the normal distribution?

Accepted Answer

A) It is almost perfectly normal. 
B) It is flatter and more spread out than the normal distribution. 
C) It is taller and narrower than the normal distribution. 
D) There is no consistent relationship between the t distribution and the normal distribution. 
A) It is almost perfectly normal. 
B) It is flatter and more spread out than the normal distribution. 
C) It is taller and narrower than the normal distribution. 
D) There is no consistent relationship between the t distribution and the normal distribution.

Question 10

For a one-tailed test with α = .05 and a sample of n = 9, the critical value for the t statistic is t = 1.860.

Accepted Answer

A) True 
 B)False

Question 11

Under what circumstances can a very small treatment effect be statistically significant?

Accepted Answer

A) if the sample size big and the sample variance is small 
B) if the sample size and the sample variance are both big 
C) if the sample size is small and the sample variance is big 
D) if the sample size and the sample variance are both small 
A) if the sample size big and the sample variance is small 
B) if the sample size and the sample variance are both big 
C) if the sample size is small and the sample variance is big 
D) if the sample size and the sample variance are both small

Question 12

If a sample of n = 16 scores is being used to make an 80% confidence interval estimate of the population mean, μ, what value(s) of t should be used?

Accepted Answer

A) t = 0 
B) t = ±2.131 
C) t = ±1.753 
D) t = ±1.341 
A) t = 0 
B) t = ±2.131 
C) t = ±1.753 
D) t = ±1.341

Question 13

If other factors are held constant, what is the effect of increasing the sample size?

Accepted Answer

A) It will increase the estimated standard error and increase the likelihood of rejecting H0. 
B) It will increase the estimated standard error and decrease the likelihood of rejecting H0. 
C) It will decrease the estimated standard error and increase the likelihood of rejecting H0. 
D) It will decrease the estimated standard error and decrease the likelihood of rejecting H0. 
A) It will increase the estimated standard error and increase the likelihood of rejecting H0. 
B) It will increase the estimated standard error and decrease the likelihood of rejecting H0. 
C) It will decrease the estimated standard error and increase the likelihood of rejecting H0. 
D) It will decrease the estimated standard error and decrease the likelihood of rejecting H0.

Question 14

Although hypothesis tests are affected by sample size, it has little or no influence on measures of effect size, such as r2 or Cohen's d.

Accepted Answer

A) True 
 B)False

Question 15

Two samples are selected from a population and a treatment is administered to the samples.If both samples have the same mean and the same variance, you are more likely to find a significant treatment effect with a sample of n = 100 than with a sample of n = 4.

Accepted Answer

A) True 
 B)False

Question 16

A sample of n = 25 scores has a mean of M = 65 and an estimated standard error of 2 points.What is the sample variance?

Accepted Answer

A) s2 = 100 
B) s2 = 96 
C) s2 = 50 
D) s2 = 48 
A) s2 = 100 
B) s2 = 96 
C) s2 = 50 
D) s2 = 48

Question 17

The results of a hypothesis test are reported as follows: t(15) = 2.70, p < .05.Based on this report, how many individuals were in the sample?

Accepted Answer

A) 14 
B) 15 
C) 16 
D) cannot be determined from the information provided 
A) 14 
B) 15 
C) 16 
D) cannot be determined from the information provided

Question 18

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, the size of the treatment effect, as measured by Cohen's d, is ____.

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 19

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. 
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.

Question 20

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

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

For a two-tailed test with α = .05 and a sample of n = 16, the boundaries for the critical region are t = ±2.120.

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?

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

A researcher conducts a hypothesis test using a sample of n = 40 from an unknown population.What is the df value for the t statistic?

If two samples are selected from the same population, under what circumstances will the two samples have exactly the same t statistic?

A sample of n = 25 scores produces a t statistic of t = -2.062.If the researcher is using a two-tailed test, then which of the following is the correct statistical decision?

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?

When n is small (less than 30), how does the shape of the t distribution compare to the normal distribution?

For a one-tailed test with α = .05 and a sample of n = 9, the critical value for the t statistic is t = 1.860.

Under what circumstances can a very small treatment effect be statistically significant?

If a sample of n = 16 scores is being used to make an 80% confidence interval estimate of the population mean, μ, what value(s) of t should be used?

If other factors are held constant, what is the effect of increasing the sample size?

Although hypothesis tests are affected by sample size, it has little or no influence on measures of effect size, such as r² or Cohen's d.

Two samples are selected from a population and a treatment is administered to the samples.If both samples have the same mean and the same variance, you are more likely to find a significant treatment effect with a sample of n = 100 than with a sample of n = 4.

A sample of n = 25 scores has a mean of M = 65 and an estimated standard error of 2 points.What is the sample variance?

The results of a hypothesis test are reported as follows: t(15) = 2.70, p < .05.Based on this report, how many individuals were in the sample?

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, the size of the treatment effect, as measured by Cohen's d, is ____.

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?

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

Introduction to Statistics

Frequency Distributions

Central Tendency

Variability

Z-Scores

Probability

The Distribution of Sample Means

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 Anova

Two-Factor Analysis of Variance

Correlation

Introduction to Regression

Chi-Square Tests

The Binomial Test

Choosing the Right Statistics

Filters

Exam 9: Introduction to the T Statistic

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

For a two-tailed test with α = .05 and a sample of n = 16, the boundaries for the critical region are t = ±2.120.

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?

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

A researcher conducts a hypothesis test using a sample of n = 40 from an unknown population.What is the df value for the t statistic?

If two samples are selected from the same population, under what circumstances will the two samples have exactly the same t statistic?

A sample of n = 25 scores produces a t statistic of t = -2.062.If the researcher is using a two-tailed test, then which of the following is the correct statistical decision?

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?

When n is small (less than 30), how does the shape of the t distribution compare to the normal distribution?

For a one-tailed test with α = .05 and a sample of n = 9, the critical value for the t statistic is t = 1.860.

Under what circumstances can a very small treatment effect be statistically significant?

If a sample of n = 16 scores is being used to make an 80% confidence interval estimate of the population mean, μ, what value(s) of t should be used?

If other factors are held constant, what is the effect of increasing the sample size?

Although hypothesis tests are affected by sample size, it has little or no influence on measures of effect size, such as r2 or Cohen's d.

Two samples are selected from a population and a treatment is administered to the samples.If both samples have the same mean and the same variance, you are more likely to find a significant treatment effect with a sample of n = 100 than with a sample of n = 4.

A sample of n = 25 scores has a mean of M = 65 and an estimated standard error of 2 points.What is the sample variance?

The results of a hypothesis test are reported as follows: t(15) = 2.70, p < .05.Based on this report, how many individuals were in the sample?

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, the size of the treatment effect, as measured by Cohen's d, is ____.

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?

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

Introduction to Statistics

Frequency Distributions

Central Tendency

Variability

Z-Scores

Probability

The Distribution of Sample Means

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 Anova

Two-Factor Analysis of Variance

Correlation

Introduction to Regression

Chi-Square Tests

The Binomial Test

Choosing the Right Statistics

Filters

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?

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

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?

Although hypothesis tests are affected by sample size, it has little or no influence on measures of effect size, such as r² or Cohen's d.

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, the size of the treatment effect, as measured by Cohen's d, is ____.