Question 1

If you are testing to see if a weight loss program is working,and you subtract the weights after − before for a group of 10 people,the alternative hypothesis is that the mean difference is ____________________ 0.

Accepted Answer

The answer of If you are testing to see if...

Question 2

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 3

In a matched pairs experiment the parameter of interest is the ____________________ of the population of ____________________.

Accepted Answer

The answer of In a matched pairs experiment the parameter...

Question 4

The degrees of freedom for a test of the mean of the paired differences is the number of ____________________ minus ____________________.

Accepted Answer

The answer of The degrees of freedom for a test...

Question 5

If there are 10 pairs of data in a matched pairs experiment,the degrees of freedom for the corresponding t-test is 18.

Accepted Answer

The degrees of freedom for the corresponding t-test in a matched pairs experiment is n-1, where n is the number of pairs. Therefore, the degrees of freedom in this case would be 9, not 18.

Question 6

Engine Wear
 To compare the wearing of two types of automobile engines,1 and 2,an experimenter chose to "pair" the measurements,comparing the wear for the two types of engines on each of 7 automobiles,as shown below.  ​ ​
-{Engine Wear Narrative} Estimate with 90% confidence the mean difference and interpret.

Accepted Answer

The answer of  Engine Wear
 To compare the wearing...

Question 7

If some natural relationship exists between each pair of observations that provides a logical reason to compare the first observation of sample 1 with the first observation of sample 2,the second observation of sample 1 with the second observation of sample 2,and so on,the samples are referred to as:

Accepted Answer

Matched pairs are pairs of observations that are related in a natural or logical way, such as a before-and-after scenario or identical twins. In this case, the first observation of sample 1 would be matched with the first observation of sample 2, and so on. Therefore, the best choice is A, matched pairs.

Question 8

If you are testing to see if a weight loss program is working,and you subtract the weights before − after for a group of 10 people,the alternative hypothesis is that the mean difference is ____________________ 0.

Accepted Answer

The answer of If you are testing to see if...

Question 9

In testing for a mean difference the null hypothesis is:

Accepted Answer

The null hypothesis in testing for a mean difference states that there is no significant difference between the means of two populations. None of the other answer choices provide an accurate representation of the null hypothesis.

Question 10

A Marine boot camp instructor recorded the time in which each of 15 recruits completed an obstacle course both before and after basic training.To test whether any improvement occurred,the instructor would use a t-distribution with 15 degrees of freedom.

Accepted Answer

The instructor would use a t-distribution with 14 degrees of freedom because the degrees of freedom for a paired sample t-test is calculated as n - 1, where n is the number of pairs (in this case, 15 recruits), so 15 - 1 = 14.

Question 11

When comparing two population means using data that are gathered from a matched pairs experiment,the test statistic for μ_D is Student t-distributed with v = n_D − 1 degrees of freedom,provided that the differences are normally distributed.

Accepted Answer

This statement is true. The matched pairs t-test is used to compare the means of two populations where the data is dependent (i.e. matched pairs or before/after measurements). The test statistic used for this test is the t-statistic, which follows a Student t-distribution with v = n-1 degrees of freedom, where n is the sample size. In this case, the sample size is equal to the number of matched pairs, so the degrees of freedom are equal to the number of pairs minus 1. The assumption of normality is necessary for the validity of the t-test.

Question 12

The test for the mean difference in a matched pairs design requires the differences to have a(n)____________________ distribution.

Accepted Answer

The answer of The test for the mean difference in...

Question 13

The number of degrees of freedom associated with the t-test,when the data are gathered from a matched pairs experiment with 10 pairs,is:

Accepted Answer

In a matched pairs experiment, each pair of individuals is matched based on some characteristic (such as age, gender, or pre-test score). This reduces the variability in the data compared to independent samples, and therefore reduces the number of degrees of freedom. The formula for calculating degrees of freedom for the t-test in a matched pairs experiment is (n-1), where n is the number of pairs. Therefore, for 10 pairs, the number of degrees of freedom is (10-1) = 9.

Question 14

In comparing two population means of interval data,we must decide whether the samples are independent (in which case the parameter of interest is )or matched pairs (in which case the parameter is μ_D)in order to select the correct test statistic.

Accepted Answer

This statement is true. Whether the samples are independent or matched pairs affects the calculation of the test statistic used to compare the population means. Independent samples require the use of the two-sample t-test, while matched pairs require the use of the paired or dependent samples t-test.

Question 15

The number of degrees of freedom associated with the t-test,when the data are gathered from a matched pairs experiment with 8 pairs,is 7.

Accepted Answer

In a matched pairs experiment, the degree of freedom is one less than the number of pairs. Therefore, in this case, the degree of freedom would be 8-1=7.

Question 16

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

When the paired differences are normal, the appropriate distribution for testing the difference between two population means is the Student t-distribution. This is because the paired differences are used to calculate the sample mean difference and the sample standard deviation of the differences, which are used to calculate the t-statistic.

Question 17

The symbol  refers to:

Accepted Answer

The answer of The symbol  refers to:
...

Question 18

Engine Wear
 To compare the wearing of two types of automobile engines,1 and 2,an experimenter chose to "pair" the measurements,comparing the wear for the two types of engines on each of 7 automobiles,as shown below.  ​ ​
-(Engine Wear Narrative} Determine whether these data are sufficient to infer at the 10% significance level that the two types of engines wear differently.

Accepted Answer

The answer of  Engine Wear
 To compare the wearing...

Question 19

Promotional Campaigns 
The general manager of a chain of fast food chicken restaurants wants to determine how effective their promotional campaigns are.In these campaigns "20% off" coupons are widely distributed.These coupons are only valid for one week.To examine their effectiveness,the executive records the daily gross sales (in $1,000s)in one restaurant during the campaign and during the week after the campaign ends.The data is shown below.  ​ ​
-{Promotional Campaigns Narrative} Can they infer at the 5% significance level that sales increase during the campaign?

Accepted Answer

The answer of Promotional Campaigns 
The general manager of a...

Question 20

In testing the hypothesis  ,two random samples from two normal populations produced the following statistics:  .What conclusion can we draw at the 1% significance level?

Accepted Answer

The answer of In testing the hypothesis  ,two random...

Quiz 13: Inference About Comparing Two Populations

If you are testing to see if a weight loss program is working,and you subtract the weights after − before for a group of 10 people,the alternative hypothesis is that the mean difference is ____________________ 0.

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

In a matched pairs experiment the parameter of interest is the of the population of .

The degrees of freedom for a test of the mean of the paired differences is the number of minus .

If there are 10 pairs of data in a matched pairs experiment,the degrees of freedom for the corresponding t-test is 18.

If you are testing to see if a weight loss program is working,and you subtract the weights before − after for a group of 10 people,the alternative hypothesis is that the mean difference is ____________________ 0.

In testing for a mean difference the null hypothesis is:

A Marine boot camp instructor recorded the time in which each of 15 recruits completed an obstacle course both before and after basic training.To test whether any improvement occurred,the instructor would use a t-distribution with 15 degrees of freedom.

When comparing two population means using data that are gathered from a matched pairs experiment,the test statistic for μ_D is Student t-distributed with v = n_D − 1 degrees of freedom,provided that the differences are normally distributed.

The test for the mean difference in a matched pairs design requires the differences to have a(n)____________________ distribution.

The number of degrees of freedom associated with the t-test,when the data are gathered from a matched pairs experiment with 10 pairs,is:

In comparing two population means of interval data,we must decide whether the samples are independent (in which case the parameter of interest is )or matched pairs (in which case the parameter is μ_D)in order to select the correct test statistic.

The number of degrees of freedom associated with the t-test,when the data are gathered from a matched pairs experiment with 8 pairs,is 7.

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:

The symbol refers to:

In testing the hypothesis ,two random samples from two normal populations produced the following statistics: .What conclusion can we draw at the 1% significance level?

Quiz 13: Inference About Comparing Two Populations

If you are testing to see if a weight loss program is working,and you subtract the weights after − before for a group of 10 people,the alternative hypothesis is that the mean difference is ____________________ 0.

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

In a matched pairs experiment the parameter of interest is the ____________________ of the population of ____________________.

The degrees of freedom for a test of the mean of the paired differences is the number of ____________________ minus ____________________.

If there are 10 pairs of data in a matched pairs experiment,the degrees of freedom for the corresponding t-test is 18.

If you are testing to see if a weight loss program is working,and you subtract the weights before − after for a group of 10 people,the alternative hypothesis is that the mean difference is ____________________ 0.

In testing for a mean difference the null hypothesis is:

A Marine boot camp instructor recorded the time in which each of 15 recruits completed an obstacle course both before and after basic training.To test whether any improvement occurred,the instructor would use a t-distribution with 15 degrees of freedom.

When comparing two population means using data that are gathered from a matched pairs experiment,the test statistic for μD is Student t-distributed with v = nD − 1 degrees of freedom,provided that the differences are normally distributed.

The test for the mean difference in a matched pairs design requires the differences to have a(n)____________________ distribution.

The number of degrees of freedom associated with the t-test,when the data are gathered from a matched pairs experiment with 10 pairs,is:

In comparing two population means of interval data,we must decide whether the samples are independent (in which case the parameter of interest is )or matched pairs (in which case the parameter is μD)in order to select the correct test statistic.

The number of degrees of freedom associated with the t-test,when the data are gathered from a matched pairs experiment with 8 pairs,is 7.

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:

The symbol refers to:

In testing the hypothesis ,two random samples from two normal populations produced the following statistics: .What conclusion can we draw at the 1% significance level?

In a matched pairs experiment the parameter of interest is the of the population of .

The degrees of freedom for a test of the mean of the paired differences is the number of minus .

When comparing two population means using data that are gathered from a matched pairs experiment,the test statistic for μ_D is Student t-distributed with v = n_D − 1 degrees of freedom,provided that the differences are normally distributed.

In comparing two population means of interval data,we must decide whether the samples are independent (in which case the parameter of interest is )or matched pairs (in which case the parameter is μ_D)in order to select the correct test statistic.