Question 1

A hypothesis test produces a t statistic of t = 2.20.If the researcher is using a two-tailed test with α = .05,how large does the sample have to be in order to reject the null hypothesis?​

Accepted Answer

A) ​At least n = 11 
B) ​At least n = 12 
C) ​At least n = 13 
D) ​At least n = 14

Question 2

What value is estimated with a confidence interval using the t statistic?​

Accepted Answer

A) ​The value for an unknown sample mean 
B) ​The value for an unknown population mean 
C) ​The difference between two population means 
D) ​The difference between two sample means

Question 3

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

Accepted Answer

A) True 
 B)False

Question 4

Two samples from same population probably will have different t statistics even if they are the same size and have the same mean.

Accepted Answer

A) True 
 B)False

Question 5

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

Accepted Answer

A) True 
 B)False

Question 6

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 7

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.

Question 8

Although you can compute a z-score for a single score (a sample of n = 1),it is impossible to compute a t statistic for a sample that has only one score.Explain why.

Accepted Answer

The answer of Although you can compute a z-score for...

Question 9

If the 90% confidence interval for µ is from 40 to 50,then the sample mean is M = 45.

Accepted Answer

A) True 
 B)False

Question 10

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

Accepted Answer

A) ​M = 85 for a sample of n = 25 
B) ​M = 85 for a sample of n = 100 
C) ​M = 90 for a sample of n = 25 
D) ​M = 90 for a sample of n = 100

Question 11

If the null hypothesis states that m = 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 12

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 13

A sample with a mean of M = 40 and a variance of s2 = 20 has an estimated standard error of 2 points.How many scores are in the sample?​

Accepted Answer

A) 4​ 
B) ​5 
C) ​10 
D) ​25

Question 14

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 15

If other factors are held constant,the bigger the sample is,the greater the likelihood of rejecting the null hypothesis.

Accepted Answer

A) True 
 B)False

Question 16

A sample of n = 25 scores has a mean of M = 40 and a variance of s2 = 100.What is the estimated standard error for the sample mean??

Accepted Answer

A) 4? 
B) ?2 
C) ? $\sqrt { 2 }$ 
D) ?1

Question 17

For a one tailed test evaluating a treatment that is supposed to decrease scores,a researcher obtains t(8)= 1.90.For α = .05,the correct decision is to reject the null hypothesis.

Accepted Answer

A) True 
 B)False

Question 18

A sample of n = 4 scores has SS = 48.What is the estimated standard error for the sample mean?​

Accepted Answer

A) 1​ 
B) ​2 
C) ​4 
D) ​16

Question 19

A researcher is testing the effect of a new cold and flu medication on mental alertness.A sample of n = 9 college students is obtained and each student is given the normal dose of the medicine.Thirty minutes later,each student's performance is measured on a video game that requires careful attention and quick decision making.The scores for the nine students are as follows: 6,8,10,6,7,13,5,5,3.
a. Assuming that scores for students in the regular population average μ = 10, are the data sufficient to conclude that the medication has a significant effect on mental performance? Test at the .05 level of significance.
b. Compute r2, the percentage of variance explained by the treatment effect.
c. Write a sentence demonstrating how the outcome of the hypothesis test and the measure of effect size would be presented in a research report.

Accepted Answer

The answer of A researcher is testing the effect of...

Question 20

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.

Exam 9: Introduction to the T Statistic

A hypothesis test produces a t statistic of t = 2.20.If the researcher is using a two-tailed test with α = .05,how large does the sample have to be in order to reject the null hypothesis?

What value is estimated with a confidence interval using the t statistic?

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

Two samples from same population probably will have different t statistics even if they are the same size and have the same mean.

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

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

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

Although you can compute a z-score for a single score (a sample of n = 1),it is impossible to compute a t statistic for a sample that has only one score.Explain why.

If the 90% confidence interval for µ is from 40 to 50,then the sample mean is M = 45.

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

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

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?

A sample with a mean of M = 40 and a variance of s² = 20 has an estimated standard error of 2 points.How many scores are in the sample?

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

If other factors are held constant,the bigger the sample is,the greater the likelihood of rejecting the null hypothesis.

A sample of n = 25 scores has a mean of M = 40 and a variance of s² = 100.What is the estimated standard error for the sample mean??

For a one tailed test evaluating a treatment that is supposed to decrease scores,a researcher obtains t(8)= 1.90.For α = .05,the correct decision is to reject the null hypothesis.

A sample of n = 4 scores has SS = 48.What is the estimated standard error for the sample mean?

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?

Exam 9: Introduction to the T Statistic

A hypothesis test produces a t statistic of t = 2.20.If the researcher is using a two-tailed test with α = .05,how large does the sample have to be in order to reject the null hypothesis?​

What value is estimated with a confidence interval using the t statistic?​

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

Two samples from same population probably will have different t statistics even if they are the same size and have the same mean.

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

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

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

Although you can compute a z-score for a single score (a sample of n = 1),it is impossible to compute a t statistic for a sample that has only one score.Explain why.

If the 90% confidence interval for µ is from 40 to 50,then the sample mean is M = 45.

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

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

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?​

A sample with a mean of M = 40 and a variance of s2 = 20 has an estimated standard error of 2 points.How many scores are in the sample?​

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

If other factors are held constant,the bigger the sample is,the greater the likelihood of rejecting the null hypothesis.

A sample of n = 25 scores has a mean of M = 40 and a variance of s2 = 100.What is the estimated standard error for the sample mean??

For a one tailed test evaluating a treatment that is supposed to decrease scores,a researcher obtains t(8)= 1.90.For α = .05,the correct decision is to reject the null hypothesis.

A sample of n = 4 scores has SS = 48.What is the estimated standard error for the sample mean?​

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 hypothesis test produces a t statistic of t = 2.20.If the researcher is using a two-tailed test with α = .05,how large does the sample have to be in order to reject the null hypothesis?

What value is estimated with a confidence interval using the t statistic?

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

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

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

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?

A sample with a mean of M = 40 and a variance of s² = 20 has an estimated standard error of 2 points.How many scores are in the sample?

A sample of n = 25 scores has a mean of M = 40 and a variance of s² = 100.What is the estimated standard error for the sample mean??

A sample of n = 4 scores has SS = 48.What is the estimated standard error for the sample mean?

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?