Question 1

Two measurements from the same individuals is an example of data collected from a matched pairs experiment.

Accepted Answer

A) True 
 B)False

Question 2

The difference in two sample proportions is a(n)____________________ estimator of the difference in their respective population proportions.

Accepted Answer

The answer of The difference in two sample proportions is...

Question 3

Antioxidants 
A food processor wants to compare two antioxidants for their effects on retarding spoilage.Suppose 16 cuts of fresh meat are treated with antioxidant A and 16 are treated with antioxidant B,and the number of hours until spoilage begins is recorded for each of the 32 cuts of meat.The results are summarized in the table below   ​ ​
-{Antioxidants Narrative} Explain how to use the 95% confidence interval for testing the equality of the two population variances at the 5% level.

Accepted Answer

Since .208 < @#IMG-DLM& = 1 <

Question 4

Profit Margin 
An investor is considering two types of investment.She is quite satisfied that the expected profit margin on Investment 1 is higher than the expected profit margin on Investment 2.However,she is quite concerned that the risk associated with Investment 1 is higher than that of Investment 2.To help make her decision,she randomly selects seven monthly profit margins on investment 1 and ten monthly profit margins on investment 2.She finds that the sample variances of Investments 1 and 2 are 225 and 118,respectively. ​ ​
-{Profit Margin Narrative} Can she infer at the 5% significance level that the population variance of investment 1 exceeds that of investment 2?

Accepted Answer

@#IMG-DLM& . Rejection region: F > F_.05,6,9 = 3.37 Test s

Question 5

Aptitude Test Scores 
Two random samples of 40 students were drawn independently from two populations of students.Assume their aptitude tests are normally distributed (total points = 100).The following statistics regarding their scores in an aptitude test were obtained:   . ​ ​
-{Aptitude Test Scores Narrative} Test at the 5% significance level to determine whether we can infer that the two population means differ.

Accepted Answer

@#IMG-DLM& , Rejection region: | t | > t_0.025,75 = 1.99 Te

Question 6

The F-distribution can only have non-negative values.

Accepted Answer

A) True 
 B)False

Question 7

The expected value of   .

Accepted Answer

A) True 
 B)False

Question 8

Two independent samples of sizes 40 and 50 are randomly selected from two populations to test the difference between the population means   .Assume the population variances are known.The sampling distribution of the sample mean difference   is:

Accepted Answer

A) normally distributed. 
B) approximately normal. 
C) Student t-distributed with 88 degrees of freedom. 
D) None of these choices. 
A) normally distributed. 
B) approximately normal. 
C) Student t-distributed with 88 degrees of freedom. 
D) None of these choices.

Question 9

The unequal-variances test statistic of   has an approximate ____________________ distribution with   degrees of freedom.

Accepted Answer

Student t

Question 10

For testing the difference between two population proportions,the pooled proportion estimate is found by taking:

Accepted Answer

A) the proportion of successes from sample 1 plus the proportion of successes from sample 2. 
B) the total number of successes in both samples divided by the total of both sample sizes. 
C) the difference between the proportion of successes in each sample. 
D) None of these choices. 
A) the proportion of successes from sample 1 plus the proportion of successes from sample 2. 
B) the total number of successes in both samples divided by the total of both sample sizes. 
C) the difference between the proportion of successes in each sample. 
D) None of these choices.

Question 11

The F-test used for testing the difference in 2 population variances is always a one-tailed test.

Accepted Answer

A) True 
 B)False

Question 12

A test is being conducted to test the difference between two population means using data that are gathered from a matched pairs experiment.If the paired differences are normal,then the distribution used for testing is the:

Accepted Answer

A) normal distribution. 
B) binomial distribution. 
C) Student t-distribution. 
D) F-distribution. 
A) normal distribution. 
B) binomial distribution. 
C) Student t-distribution. 
D) F-distribution.

Question 13

Two independent samples of sizes 20 and 30 are randomly selected from two normally distributed populations.Assume that the population variances are unknown but equal.In order to test the difference between the population means,   ,the sampling distribution of the sample mean difference,   ,is:

Accepted Answer

A) normal. 
B) Student-t with 50 degrees of freedom. 
C) Student-t with 48 degrees of freedom. 
D) None of these choices. 
A) normal. 
B) Student-t with 50 degrees of freedom. 
C) Student-t with 48 degrees of freedom. 
D) None of these choices.

Question 14

A calculus professor wanted to test whether the grades on calculus test were the same for upper and lower classmen.The professor took a random sample of size 12 from each group.For this situation,the professor should use a matched pairs t-test.

Accepted Answer

A) True 
 B)False

Question 15

The variance of the difference in sample proportions equals the difference of their population variances.

Accepted Answer

A) True 
 B)False

Question 16

When the necessary conditions are met,a two-tail test is being conducted at α = .01 to test   .The two sample variances are   and   ,and the sample sizes are n1 = 36and n2 = 36.The calculated value of the p-value for the F test is 0.5926.

Accepted Answer

A) True 
 B)False

Question 17

A political analyst in Iowa surveys a random sample of registered Republicans and compares the results with those obtained from a random sample of registered Democrats .This would be an example of two independent samples.

Accepted Answer

A) True 
 B)False

Question 18

Mass Production Line
 A quality control examiner keeps a tally sheet of the number of acceptable and unacceptable products that come off two different production lines.The completed sheet is shown below.   ​ ​
-{Mass Production Line Narrative} What is the p-value of the test? Explain how to use it for testing the hypotheses.

Accepted Answer

p-value = .0375 Sinc

Question 19

Two measurements from the same individuals is an example of data collected from a(n)____________________ experiment.

Accepted Answer

The answer of Two measurements from the same individuals is...

Question 20

In constructing a confidence interval estimate for the difference between two population proportions,we pool the population proportions when the populations are normally distributed.

Accepted Answer

A) True 
 B)False

Two measurements from the same individuals is an example of data collected from a matched pairs experiment.

The difference in two sample proportions is a(n)____________________ estimator of the difference in their respective population proportions.

The F-distribution can only have non-negative values.

The expected value of .

Two independent samples of sizes 40 and 50 are randomly selected from two populations to test the difference between the population means .Assume the population variances are known.The sampling distribution of the sample mean difference is:

The unequal-variances test statistic of has an approximate ____________________ distribution with degrees of freedom.

For testing the difference between two population proportions,the pooled proportion estimate is found by taking:

The F-test used for testing the difference in 2 population variances is always a one-tailed test.

A test is being conducted to test the difference between two population means using data that are gathered from a matched pairs experiment.If the paired differences are normal,then the distribution used for testing is the:

Two independent samples of sizes 20 and 30 are randomly selected from two normally distributed populations.Assume that the population variances are unknown but equal.In order to test the difference between the population means, ,the sampling distribution of the sample mean difference, ,is:

A calculus professor wanted to test whether the grades on calculus test were the same for upper and lower classmen.The professor took a random sample of size 12 from each group.For this situation,the professor should use a matched pairs t-test.

The variance of the difference in sample proportions equals the difference of their population variances.

When the necessary conditions are met,a two-tail test is being conducted at α = .01 to test .The two sample variances are and ,and the sample sizes are n₁ = 36and n₂ = 36.The calculated value of the p-value for the F test is 0.5926.

A political analyst in Iowa surveys a random sample of registered Republicans and compares the results with those obtained from a random sample of registered Democrats .This would be an example of two independent samples.

Two measurements from the same individuals is an example of data collected from a(n)____________________ experiment.

In constructing a confidence interval estimate for the difference between two population proportions,we pool the population proportions when the populations are normally distributed.

What Is Statistics

Graphical Descriptive Techniques 1

Graphical Descriptive Techniques 2

Numerical Descriptive Techniques

Data Collection and Sampling

Probability

Random Variables and Discrete Probability Distributions

Continuous Probability Distributions

Sampling Distributions

Introduction to Estimation

Introduction to Hypothesis Testing

Inference About a Population

Analysis of Variance

Chi-Squared Tests

Simple Linear Regression and Correlation

Multiple Regression

Model Building

Nonparametric Statistics

Time-Series Analytics and Forecasting

Statistical Process Control

Decision Analysis

Conclusion

Filters

Exam 13: Inference About Comparing Two Populations

Two measurements from the same individuals is an example of data collected from a matched pairs experiment.

The difference in two sample proportions is a(n)____________________ estimator of the difference in their respective population proportions.

The F-distribution can only have non-negative values.

The expected value of .

Two independent samples of sizes 40 and 50 are randomly selected from two populations to test the difference between the population means .Assume the population variances are known.The sampling distribution of the sample mean difference is:

The unequal-variances test statistic of has an approximate ____________________ distribution with degrees of freedom.

For testing the difference between two population proportions,the pooled proportion estimate is found by taking:

The F-test used for testing the difference in 2 population variances is always a one-tailed test.

A test is being conducted to test the difference between two population means using data that are gathered from a matched pairs experiment.If the paired differences are normal,then the distribution used for testing is the:

Two independent samples of sizes 20 and 30 are randomly selected from two normally distributed populations.Assume that the population variances are unknown but equal.In order to test the difference between the population means, ,the sampling distribution of the sample mean difference, ,is:

A calculus professor wanted to test whether the grades on calculus test were the same for upper and lower classmen.The professor took a random sample of size 12 from each group.For this situation,the professor should use a matched pairs t-test.

The variance of the difference in sample proportions equals the difference of their population variances.

When the necessary conditions are met,a two-tail test is being conducted at α = .01 to test .The two sample variances are and ,and the sample sizes are n1 = 36and n2 = 36.The calculated value of the p-value for the F test is 0.5926.

A political analyst in Iowa surveys a random sample of registered Republicans and compares the results with those obtained from a random sample of registered Democrats .This would be an example of two independent samples.

Two measurements from the same individuals is an example of data collected from a(n)____________________ experiment.

In constructing a confidence interval estimate for the difference between two population proportions,we pool the population proportions when the populations are normally distributed.

What Is Statistics

Graphical Descriptive Techniques 1

Graphical Descriptive Techniques 2

Numerical Descriptive Techniques

Data Collection and Sampling

Probability

Random Variables and Discrete Probability Distributions

Continuous Probability Distributions

Sampling Distributions

Introduction to Estimation

Introduction to Hypothesis Testing

Inference About a Population

Analysis of Variance

Chi-Squared Tests

Simple Linear Regression and Correlation

Multiple Regression

Model Building

Nonparametric Statistics

Time-Series Analytics and Forecasting

Statistical Process Control

Decision Analysis

Conclusion

Filters

When the necessary conditions are met,a two-tail test is being conducted at α = .01 to test .The two sample variances are and ,and the sample sizes are n₁ = 36and n₂ = 36.The calculated value of the p-value for the F test is 0.5926.