Question 1

If the sample data are in the critical region with α = .01,then the same sample data would still be in the critical region if α were changed to .05.

Accepted Answer

A) True 
 B)False

Question 2

If the sample data are in the critical region with α = .05,then the same sample data would still be in the critical region if α were changed to .01.

Accepted Answer

A) True 
 B)False

Question 3

Even if a treatment has no effect,it is still possible to obtain an extreme sample mean that is very different from the population mean.What outcome is likely if this happens?

Accepted Answer

A) Reject H0 and make a Type I error 
B) Correctly reject H0 
C) Fail to reject H0 and make a Type II error 
D) Correctly fail to reject H0

Question 4

You can reduce the risk of a Type I error by using a larger sample.

Accepted Answer

A) True 
 B)False

Question 5

Withα= .05,how are the boundaries for the critical region determined?

Accepted Answer

A) Boundaries are drawn so there is 2.5% (.025) in each tail of the distribution. 
B) Boundaries are drawn so there is 5% (.05) in each tail of the distribution. 
C) Boundaries are drawn so there is 10% (.10) in each tail of the distribution. 
D) Boundaries are drawn so there is 5% (.05) in the center of the distribution.

Question 6

A Type II error occurs when a treatment actually does have an effect on the scores but the effect was not large enough to reject the null hypothesis.

Accepted Answer

A) True 
 B)False

Question 7

A treatment is administered to a sample of n = 9 individuals selected from a population with a mean of µ = 80 and a standard deviation of σ = 12.After treatment,the effect size is measured by computing Cohen's d,and a value of d = 0.50 is obtained.Based on this information,what is the mean for the treated sample?

Accepted Answer

A) M = 6 
B) M = 82 
C) M = 86 
D) Cannot answer without knowing the sample size

Question 8

You complete a hypothesis test using α = .05,and based on the evidence from the sample,your decision is to fail to reject the null hypothesis.If the treatment actually does have an effect,which of the following is true?

Accepted Answer

A) You have made a Type I error. 
B) You have made a Type II error. 
C) You might have made a Type I error, but the probability is only 5% at most. 
D) You have made the correct decision.

Question 9

If the power for a hypothesis test is calculated to be 0.80,then for same test,the probability of a Type II error is 0.20.

Accepted Answer

A) True 
 B)False

Question 10

A sample of n = 25 individuals is selected from a population with µ = 80,and a treatment is administered to the sample.What is expected if the treatment has no effect?

Accepted Answer

A) The sample mean after the treatment should be very different from 80 and should lead you to reject the null hypothesis. 
B) The sample mean after the treatment should be very different from 80 and should lead you to fail to reject the null hypothesis. 
C) The sample mean after the treatment should be close to 80 and should lead you to reject the null hypothesis. 
D) The sample mean after the treatment should be close 80 and should lead you to fail to reject the null hypothesis.

Question 11

What is the effect of decreasing the alpha level (for example,from α = .05 to α = .01)?

Accepted Answer

A) It decreases the probability of a Type I error. 
B) It decreases the size of the critical region. 
C) It decreases the probability that the sample will fall into the critical region. 
D) All of the other options are results of decreasing alpha.

Question 12

You complete a hypothesis test using α = .05,and based on the evidence from the sample,your decision is to reject the null hypothesis.Which of the following is true?

Accepted Answer

A) You have made a Type I error. 
B) You have made a Type II error. 
C) You might have made a Type I error, but the probability is less than 5%. 
D) You have made the correct decision.

Question 13

If the research prediction is that the treatment will decrease scores,then the critical region for a directional test will be in the left-hand tail.

Accepted Answer

A) True 
 B)False

Question 14

The term error is used in two different ways in hypothesis testing: a Type I error (or Type II)and the standard error.
a.What can a researcher do to influence the size of the standard error? Does this action
have any effect on the probability of a Type I error?
b.What can a researcher do to influence the probability of a Type I error? Does this
action have any effect on the size of the standard error?

Accepted Answer

The answer of The term error is used in two...

Question 15

If a treatment has a very small effect,what is a likely outcome for a hypothesis test evaluating the treatment?

Accepted Answer

A) A Type I error 
B) A Type II error 
C) Correctly reject the null hypothesis 
D) Correctly fail to reject the null hypothesis

Question 16

In a hypothesis test,the likelihood of rejecting the null hypothesis is independent of the sample size.

Accepted Answer

A) True 
 B)False

Question 17

Even if a treatment has an effect,it is still possible to obtain a sample mean after the treatment that is very similar to the original population mean.What outcome is likely if this happens?

Accepted Answer

A) Reject H0 and make a Type I error 
B) Correctly reject H0 
C) Fail to reject H0 and make a Type II error 
D) Correctly fail to reject H0

Question 18

A researcher expects a treatment to increase the scores for individuals in a population.The treatment is evaluated using a one-tailed hypothesis test,and the test produces z = +2.40.Based on this result,what is the correct statistical decision?

Accepted Answer

A) The researcher should reject the null hypothesis with α = .05 but not with α = .01. 
B) The researcher should reject the null hypothesis with either α = .05 or α = .01. 
C) The researcher should fail to reject H0 with either α = .05 or α = .01. 
D) Cannot answer without additional information

Question 19

A researcher administers a treatment to a sample of participants selected from a population with µ = 80.If a hypothesis test is used to evaluate the effect of the treatment,which combination of factors is most likely to result in rejecting the null hypothesis?

Accepted Answer

A) A sample mean near 80 for a small sample 
B) A sample mean near 80 for a large sample 
C) A sample mean much different than 80 for a small sample 
D) A sample mean much different than 80 for a large sample

Question 20

In most situations,researchers would like the hypothesis test to reject the null hypothesis.

Accepted Answer

A) True 
 B)False

Exam 8: Introduction to Hypothesis Testing.

If the sample data are in the critical region with α = .01,then the same sample data would still be in the critical region if α were changed to .05.

If the sample data are in the critical region with α = .05,then the same sample data would still be in the critical region if α were changed to .01.

Even if a treatment has no effect,it is still possible to obtain an extreme sample mean that is very different from the population mean.What outcome is likely if this happens?

You can reduce the risk of a Type I error by using a larger sample.

Withα= .05,how are the boundaries for the critical region determined?

A Type II error occurs when a treatment actually does have an effect on the scores but the effect was not large enough to reject the null hypothesis.

You complete a hypothesis test using α = .05,and based on the evidence from the sample,your decision is to fail to reject the null hypothesis.If the treatment actually does have an effect,which of the following is true?

If the power for a hypothesis test is calculated to be 0.80,then for same test,the probability of a Type II error is 0.20.

A sample of n = 25 individuals is selected from a population with µ = 80,and a treatment is administered to the sample.What is expected if the treatment has no effect?

What is the effect of decreasing the alpha level (for example,from α = .05 to α = .01) ?

You complete a hypothesis test using α = .05,and based on the evidence from the sample,your decision is to reject the null hypothesis.Which of the following is true?

If the research prediction is that the treatment will decrease scores,then the critical region for a directional test will be in the left-hand tail.

If a treatment has a very small effect,what is a likely outcome for a hypothesis test evaluating the treatment?

In a hypothesis test,the likelihood of rejecting the null hypothesis is independent of the sample size.

Even if a treatment has an effect,it is still possible to obtain a sample mean after the treatment that is very similar to the original population mean.What outcome is likely if this happens?

A researcher expects a treatment to increase the scores for individuals in a population.The treatment is evaluated using a one-tailed hypothesis test,and the test produces z = +2.40.Based on this result,what is the correct statistical decision?

A researcher administers a treatment to a sample of participants selected from a population with µ = 80.If a hypothesis test is used to evaluate the effect of the treatment,which combination of factors is most likely to result in rejecting the null hypothesis?

In most situations,researchers would like the hypothesis test to reject the null hypothesis.