Question 1

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION:
Two samples each of size 20 are taken from independent populations assumed to be normally distributed with equal variances.The first sample has a mean of 43.5 and standard deviation of 4.1 while the second sample has a mean of 40.1 and standard deviation of 3.2.A researcher would like to test if there is a difference between the population means at the 0.05 significance level.
-State the null hypothesis.

Accepted Answer

A) H0 : Px = Py 
B) H0 :  
=
  
C) H0 : μx - μy = 3.4 
D) H0 : μx - μy = 0

Question 2

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION:
Suppose two food preservatives are extensively tested and determined safe for use in meats.A processor wants to compare the preservatives for their effects on retarding spoilage.Suppose 16 cuts of fresh meat are treated with preservative A and another 12 cuts of meat are treated with preservative B.The number of hours until spoilage begins is recorded for each of the 28 cuts of meat.The results are summarized in the table below.
 
-The value of the test statistic for determining if there is a difference in the population variances for preservatives A and B is equal to:

Accepted Answer

A) 0.784 
B) 1.625 
C) 1.275 
D) 1.129

Question 3

The procedure that utilizes the normal distribution to test the difference between two population proportions is valid for all sample sizes.

Accepted Answer

A) True 
 B)False

Question 4

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION:
To investigate the effectiveness of a diet,a random sample of 16 female patients is drawn from a population of adult females using the diet.The weight of each individual in the sample is taken at the start and at the end of the diet.Assume that the population of differences in weight before and after the diet follows a normal distribution.Suppose the mean decrease in weights over all 16 subjects in the study is 4.0 pounds with the standard deviation of differences computed as 6.4 pounds.Let µS1U1B1xS1U1B0 - µS1U1B1yS1U1B0S1U1B1 S1U1B0= mean weight before the diet - mean weight after the diet.
-In order to test if the diet is effective,what is the appropriate critical value(s)at the 0.05 level of significance?

Accepted Answer

A) 2.131 
B) 2.120 
C) 1.753 
D) 1.746

Question 5

What is the value of the test statistic?

Accepted Answer

A) 2.92 
B) 0.79 
C) 3.62 
D) 1.74

Question 6

The test statistic for the equality of two population variances is based on the:

Accepted Answer

A) ratio of the two sample variances. 
B) difference between the two sample variances. 
C) difference between the two population variances. 
D) difference between the sample variances divided by the difference between the sample means.

Question 7

In a random sample of 150 music industry management majors,75 rated a sense of humor as very important trait to their career performance.The same view was held by 81 of an independent random sample of 180 professional golf management majors.Test at the 5% level against a two-sided alternative the null hypothesis that the population proportions of music industry management and professional golf management majors who rate a sense of humor as very important are the same.

Accepted Answer

The answer of In a random sample of 150 music...

Question 8

When testing for the difference between the means of two independent populations with equal variances and with samples of sizes n1 = 20 and n2 = 20,what is the number of degrees of freedom?

Accepted Answer

A) 40 
B) 38 
C) 20 
D) 19

Question 9

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION:
As part of its quality control program,the Scullia Auto Company (SAC)began inspecting all supplier shipments of steel bars and recording the defect rate according to quality criteria such as strength,dimensional characteristics,etc.When SAC began this program,the defect rate in 100 shipments averaged 9%.A recent report indicated an average defect rate of 2.2% in 136 shipments.The quality control department wants to determine,at the 0.05 level of significance,if this represents a significant improvement in the quality of the steel.
-What is the test statistic?

Accepted Answer

The answer of THE NEXT QUESTIONS ARE BASED ON THE...

Question 10

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION:
The sociological department of Kent College conducted an investigation to determine how long it takes for a woman or man to get married after their graduation in Kent Town.Two independent random samples were selected and the following summary information concerning times to completion of medical school were computed:
 
-Find the p-value associated with the test of hypothesis to determine whether there is a significant difference in time to completion of medical school between women and men and explain how to use it for testing the hypothesis using α = 0.05.

Accepted Answer

The answer of THE NEXT QUESTIONS ARE BASED ON THE...

Question 11

Hypothesis tests that use the F distribution do not depend on the assumption that the populations are normally distributed as long as the sample sizes are large.

Accepted Answer

A) True 
 B)False

Question 12

For two independent random samples with nx and ny observations,and each following a normal distribution,which of the following would be the F distribution degrees of freedom in the numerator?

Accepted Answer

A) nx - 1 
B) nx + 1 
C) 1 -  
D) ny - 1

Question 13

In what type of test is the variable of interest the difference between the values of the observations rather than the observations themselves?

Accepted Answer

A) a test of the equality of variances from 2 independent populations 
B) a test of the difference between the means of 2 related populations 
C) a test of the difference between the means of 2 independent populations 
D) a test for of equality of variances from two related populations.

Question 14

The F test used for testing the difference in two population variances is always a one-tailed test.

Accepted Answer

A) True 
 B)False

Question 15

When testing for differences between the means of two independent populations,only a t-test can be used.

Accepted Answer

A) True 
 B)False

Question 16

To use the Student's t distribution to compare population means when the population variances are unknown and sample sizes are small,the populations are assumed to be normally distributed.

Accepted Answer

A) True 
 B)False

Question 17

Assuming the independent samples procedure was used,which of the following is the correct test statistic.

Accepted Answer

A) Z =  
B) Z =  
C) Z =  
D) Z =

Question 18

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION:
To investigate the effectiveness of a diet,a random sample of 16 female patients is drawn from a population of adult females using the diet.The weight of each individual in the sample is taken at the start and at the end of the diet.Assume that the population of differences in weight before and after the diet follows a normal distribution.Suppose the mean decrease in weights over all 16 subjects in the study is 4.0 pounds with the standard deviation of differences computed as 6.4 pounds.Let µS1U1B1xS1U1B0 - µS1U1B1yS1U1B0S1U1B1 S1U1B0= mean weight before the diet - mean weight after the diet.
-In order to test if the diet is effective,what is the appropriate alternative hypothesis?

Accepted Answer

A) H1 : μd 1 : μd > 0 
C) H1 : μd = 0 
D) H1 : μd ≠ 0

Question 19

When testing for the difference between the means of two independent populations,with samples of sizes n1 and n2,where the population variances are unknown but assumed to be equal,what is the number of degrees of freedom?

Accepted Answer

A) n - 1 
B) n1 + n2 - 1 
C) n1 + n2 - 2 
D) n - 2

Question 20

When testing for the difference between two population variances with sample sizes of n1 = 10 and n2 = 12,what is (are)the number (s)of degrees of freedom?

Accepted Answer

A) 10 and 12 
B) 9 and 11 
C) 22 
D) 20

Exam 10: Hypothesis Testing: Additional Topics

The procedure that utilizes the normal distribution to test the difference between two population proportions is valid for all sample sizes.

What is the value of the test statistic?

The test statistic for the equality of two population variances is based on the:

When testing for the difference between the means of two independent populations with equal variances and with samples of sizes n₁ = 20 and n₂ = 20,what is the number of degrees of freedom?

Hypothesis tests that use the F distribution do not depend on the assumption that the populations are normally distributed as long as the sample sizes are large.

For two independent random samples with n_x and n_y observations,and each following a normal distribution,which of the following would be the F distribution degrees of freedom in the numerator?

In what type of test is the variable of interest the difference between the values of the observations rather than the observations themselves?

The F test used for testing the difference in two population variances is always a one-tailed test.

When testing for differences between the means of two independent populations,only a t-test can be used.

To use the Student's t distribution to compare population means when the population variances are unknown and sample sizes are small,the populations are assumed to be normally distributed.

Assuming the independent samples procedure was used,which of the following is the correct test statistic.

When testing for the difference between the means of two independent populations,with samples of sizes n₁and n₂,where the population variances are unknown but assumed to be equal,what is the number of degrees of freedom?

When testing for the difference between two population variances with sample sizes of n₁ = 10 and n₂ = 12,what is (are) the number (s) of degrees of freedom?

Exam 10: Hypothesis Testing: Additional Topics

The procedure that utilizes the normal distribution to test the difference between two population proportions is valid for all sample sizes.

What is the value of the test statistic?

The test statistic for the equality of two population variances is based on the:

When testing for the difference between the means of two independent populations with equal variances and with samples of sizes n1 = 20 and n2 = 20,what is the number of degrees of freedom?

Hypothesis tests that use the F distribution do not depend on the assumption that the populations are normally distributed as long as the sample sizes are large.

For two independent random samples with nx and ny observations,and each following a normal distribution,which of the following would be the F distribution degrees of freedom in the numerator?

In what type of test is the variable of interest the difference between the values of the observations rather than the observations themselves?

The F test used for testing the difference in two population variances is always a one-tailed test.

When testing for differences between the means of two independent populations,only a t-test can be used.

To use the Student's t distribution to compare population means when the population variances are unknown and sample sizes are small,the populations are assumed to be normally distributed.

Assuming the independent samples procedure was used,which of the following is the correct test statistic.

When testing for the difference between the means of two independent populations,with samples of sizes n1 and n2,where the population variances are unknown but assumed to be equal,what is the number of degrees of freedom?

When testing for the difference between two population variances with sample sizes of n1 = 10 and n2 = 12,what is (are) the number (s) of degrees of freedom?

When testing for the difference between the means of two independent populations with equal variances and with samples of sizes n₁ = 20 and n₂ = 20,what is the number of degrees of freedom?

For two independent random samples with n_x and n_y observations,and each following a normal distribution,which of the following would be the F distribution degrees of freedom in the numerator?

When testing for the difference between the means of two independent populations,with samples of sizes n₁and n₂,where the population variances are unknown but assumed to be equal,what is the number of degrees of freedom?

When testing for the difference between two population variances with sample sizes of n₁ = 10 and n₂ = 12,what is (are) the number (s) of degrees of freedom?