Chapter 10: Statistical Inference about Means and Proportions with Two Populations

An instructor would like to compare the test one grades in the 10:00 statistics class to the grades in the 11:00 class. The instructor takes a sample of 10 test one grades from each of the classes. This is an example of
1. matched sampling
2. independent sampling
A grocery store manager would like to compare prices as her store to the prices at a competitor. She chooses a sample of 15 items that are sold at both stores and compares the prices. This is an example of
1. matched sampling.
2. independent sampling
testing company is checking to see whether there is any significant difference in the coverage of two different brands of paint for a hardware store chain. The results are summarized below.

A point estimate of the difference between the population means is
1. -5
2. 0
3. 5
4. 10
A testing company is checking to see whether there is any significant difference in the coverage of two different brands of paint for a hardware store chain. The results are summarized below.

A point estimate of the standard deviation of the difference between the sample means is
1. 2.624
2. 4.888
3. 6.889
4. 23.889
A testing company is checking to see whether there is any significant difference in the coverage of two different brands of paint for a hardware store chain. The results are summarized below.

The form of the sampling distribution of the difference between the sample means is the
1. normal distribution, approximately
2. t distribution with 28 degrees of freedom
3. t distribution with 30 degrees of freedom
4. t distribution with 417 degrees of freedom
A testing company is checking to see whether there is any significant difference in the coverage of two different brands of paint for a hardware store chain. The results are summarized below.

If a two-tailed test is used, the p-value is
1. approximately 0
2. .0202
3. .0404
4. .4798
A testing company is checking to see whether there is any significant difference in the coverage of two different brands of paint for a hardware store chain. The results are summarized below.

If a two-tailed test is used with a .05 level of significance, the decision is
1. do not reject the null hypothesis
2. reject the null hypothesis
An instructor wanted to compare how students did on their first test compared to their second test. A sample of seven students was chosen and their first and second test scores were recorded.

This is an example of
1. matched sampling
2. independent sampling
An instructor wanted to compare how students did on their first test compared to their second test. A sample of seven students was chosen and their first and second test scores were recorded.

The instructor's hypothesis is that there is no difference between the average test scores. The test is done with a = .05. The critical value is.
1. -2.447 and 2.447
2. -.196 and 1.96
3. -1.943
4. 1.943
An instructor wanted to compare how students did on their first test compared to their second test. A sample of seven students was chosen and their first and second test scores were recorded.

The instructor's hypothesis is that there is no difference between the average test scores. The test is done with a = .05. An estimate of the population mean difference between the test scores is
1. 2.33
2. 2.43
3. 2.76
4. 3
An instructor wanted to compare how students did on their first test compared to their second test. A sample of seven students was chosen and their first and second test scores were recorded.

The instructor's hypothesis is that there is no difference between the average test scores. The test is done with a = .05. The standard deviation of the difference between the test scores is
1. 2.33
2. 2.43
3. 2.76
4. 3
An instructor wanted to compare how students did on their first test compared to their second test. A sample of seven students was chosen and their first and second test scores were recorded.

The instructor's hypothesis is that there is no difference between the average test scores. The appropriate test statistic follows the following distribution:
1. Standard normal distribution
2. t-distribution with 6 degrees of freedom
3. t-distribution with 12 degrees of freedom
4. None of the choices is correct
An instructor wanted to compare how students did on their first test compared to their second test. A sample of seven students was chosen and their first and second test scores were recorded.

The instructor's hypothesis is that there is no difference between the average test scores. The test is done with α = .05. The decision is
1. reject the null hypothesis
2. do not reject the null hypothesis
A survey firm conducts door-to-door surveys on a variety of issues. Some individuals cooperate with the interviewer and complete the interview questionnaire and others do not. The following data are available.

Give a point estimate of the difference between the population proportions for women and men.
1. 0.15
2. 0.55
3. 0.70
4. 100
5. None of the above
A survey firm conducts door-to-door surveys on a variety of issues. Some individuals cooperate with the interviewer and complete the interview questionnaire and others do not. The following data are available.

Give a 95% confidence interval estimate of the difference between the population proportions for women and men.
1. 0.064 to 0.236
2. 0.106 to 0.194
3. 0.12 to 0.18
4. 0.144 to 0.156
5. None of the above