Question 1

We want to see if the workers on the day and night shifts differ significantly in their productivity levels. A sample of workers from both shifts was taken.  
a.State the null and alternative hypotheses.
b.Test the null hypothesis at the 5% level of significance.

Accepted Answer

The answer of We want to see if the workers...

Question 2

The following data show the test scores of six individuals on a standardized test before and after attending a preparation seminar for the test.  Use the Wilcoxon Signed-Rank test in order to determine whether or nor the seminar has been effective. Hint: This is a one tailed test. Let $\alpha$ = 0.05.

Accepted Answer

The answer of The following data show the test scores...

Question 3

The manager of a company believes that differences in sales performance depends upon the salesperson's age. Independent samples of salespeople were taken and their weekly sales record is reported below.  
a.State the null and alternative hypotheses.
b.At 95% confidence, test the hypotheses.

Accepted Answer

The answer of The manager of a company believes that...

Question 4

In a sample of 120 people, 50 indicated that they prefer domestic automobiles, 60 said they prefer foreign-made cars, and 10 indicated no difference in their preference. At a 0.05 level of significance, determine if there is evidence of a significant difference in the preferences for the two makes of automobiles.

Accepted Answer

The answer of In a sample of 120 people, 50...

Question 5

A clothing manufacturer purchased some newly designed sewing machines in the hopes that production would be increased. The production records of a random sample of workers are shown below.  Use the Wilcoxon signed-rank test to determine whether the new machines have significantly increased production. Use a .05 level of significance.

Accepted Answer

The answer of A clothing manufacturer purchased some newly designed...

Question 6

In a sample of 300 shoppers, 160 indicated they prefer fluoride toothpaste, 120 favored nonfluoride, and 20 were indifferent. At a 0.05 level of significance, test for a difference in the preference for the two kinds of toothpaste.

Accepted Answer

The answer of In a sample of 300 shoppers, 160...

Question 7

Two groups of students were asked to rank the activities sponsored by the Student Government Association on campus. The following show their rankings.  Determine the Spearman rank-correlation coefficient and test for a significant correlation with $\alpha$= 0.05.

Accepted Answer

The answer of Two groups of students were asked to...

Question 8

A survey of male and female students showed the following ranking of 12 professors in the management department:  Do the rankings given by the female students agree with the rankings given by the male students? Use $\alpha$ = 0.05.

Accepted Answer

The answer of A survey of male and female students...

Question 9

Fifteen people were asked to indicate their preference for domestic versus imported cars. The following data showed their preferences.  With $\alpha$ = 0.05, test for a significant difference in the preferences for cars. A "+" indicates a preference for imported cars.

Accepted Answer

The answer of Fifteen people were asked to indicate their...

Question 10

Two faculty members ranked 12 candidates for scholarships. Calculate the Spearman rank-correlation coefficient and test it for significance. Use a .02 level of significance.

Accepted Answer

The answer of Two faculty members ranked 12 candidates for...

Question 11

Two employers (A and B) ranked five candidates for a new position. Their rankings of the candidates are shown below.  Compute the Spearman rank-correlation and test it for significance. Let $\alpha$ = 0.05.

Accepted Answer

The answer of Two employers (A and B) ranked five...

Question 12

A PTA group wishes to determine whether a barrage of letters sent to the local station has reduced the amount of violence broadcast between the hours of 4 P.M. and 9 P.M. The results of a survey of viewers are given here.  Carry out a sign test to determine whether or not the letters were effective in reducing the amount of violence during the 4 to 9 p.m. period. Use a .05 level of significance. Be sure to state the null and alternative hypotheses.

Accepted Answer

The answer of A PTA group wishes to determine whether...

Question 13

It is believed that the median age of college students is 21 years. A sample of 80 college students is taken. Thirty of the students were under 21, 45 of the students were over 21, and 10 were 21 years old.
a.State the null and alternative hypotheses.
b.Test the null hypothesis at the 1% level of significance.

Accepted Answer

The answer of It is believed that the median age...

Question 14

Two individuals were asked to rank the performances of eight different automobiles. The following show their rankings.  Determine the Spearman rank-correlation coefficient; and at 95% confidence, test for its significance.

Accepted Answer

The answer of Two individuals were asked to rank the...

Question 15

Test scores of ten individuals before and after a training program are shown below.  At$\alpha$ = 0.05, what can be concluded about the effectiveness of the training program?

Accepted Answer

The answer of Test scores of ten individuals before and...

Question 16

A comprehensive statistics examination is given to 16 students in order to determine whether or not there is a significant difference in the performance of students majoring in the various disciplines of Business Administration. The following data show the scores of the 16 students (5 majoring in accounting, 6 majoring in management, and 5 majoring in marketing).  At $\alpha$= 0.05 level of significance, test to see if there is a significant difference in the performance of the students in the three majors.

Accepted Answer

The answer of A comprehensive statistics examination is given to...

Question 17

The following data show the preference of 20 people for a candidate to a public office. A "+" indicates a preference for the Democratic candidate, and a "-" indicates a preference for the Republican candidate.  With $\alpha$ = 0.05, test for a significant difference in the preference for the candidates.

Accepted Answer

The answer of The following data show the preference of...

Question 18

Ten drivers were asked to drive two models of a car. Each car was given one gallon of gasoline. The distance that each automobile traveled on a gallon of gasoline is shown below.  At$\alpha$ = 0.05, what can be concluded about the performance of the two models?

Accepted Answer

The answer of Ten drivers were asked to drive two...

Question 19

Two faculty members (X and Y) ranked five candidates for scholarships. The rankings are shown below.  Compute the Spearman rank-correlation and test it for significance. Let $\alpha$ = 0.05.

Accepted Answer

The answer of Two faculty members (X and Y) ranked...

Question 20

The president of a company wants to see if the new anti-smoking campaign is having any influence on his employees. A sample of 100 employees who smoked prior to the campaign is taken. Thirty-six employees said they smoked less, 15 employees said they smoked more, and 49 employees said there was no change.
a.State the null and alternative hypotheses.
b.Test the null hypothesis at the 1% level of significance.

Accepted Answer

The answer of The president of a company wants to...

Quiz 18: Nonparametric Methods

We want to see if the workers on the day and night shifts differ significantly in their productivity levels. A sample of workers from both shifts was taken. a.State the null and alternative hypotheses. b.Test the null hypothesis at the 5% level of significance.

The manager of a company believes that differences in sales performance depends upon the salesperson's age. Independent samples of salespeople were taken and their weekly sales record is reported below. a.State the null and alternative hypotheses. b.At 95% confidence, test the hypotheses.

In a sample of 300 shoppers, 160 indicated they prefer fluoride toothpaste, 120 favored nonfluoride, and 20 were indifferent. At a 0.05 level of significance, test for a difference in the preference for the two kinds of toothpaste.

Two groups of students were asked to rank the activities sponsored by the Student Government Association on campus. The following show their rankings. Determine the Spearman rank-correlation coefficient and test for a significant correlation with α\alphaα = 0.05.

A survey of male and female students showed the following ranking of 12 professors in the management department: Do the rankings given by the female students agree with the rankings given by the male students? Use α\alphaα = 0.05.

Fifteen people were asked to indicate their preference for domestic versus imported cars. The following data showed their preferences. With α\alphaα = 0.05, test for a significant difference in the preferences for cars. A "+" indicates a preference for imported cars.

Two faculty members ranked 12 candidates for scholarships. Calculate the Spearman rank-correlation coefficient and test it for significance. Use a .02 level of significance.

Two employers (A and B) ranked five candidates for a new position. Their rankings of the candidates are shown below. Compute the Spearman rank-correlation and test it for significance. Let α\alphaα = 0.05.

Two individuals were asked to rank the performances of eight different automobiles. The following show their rankings. Determine the Spearman rank-correlation coefficient; and at 95% confidence, test for its significance.

Test scores of ten individuals before and after a training program are shown below. At α\alphaα = 0.05, what can be concluded about the effectiveness of the training program?

Ten drivers were asked to drive two models of a car. Each car was given one gallon of gasoline. The distance that each automobile traveled on a gallon of gasoline is shown below. At α\alphaα = 0.05, what can be concluded about the performance of the two models?

Two faculty members (X and Y) ranked five candidates for scholarships. The rankings are shown below. Compute the Spearman rank-correlation and test it for significance. Let α\alphaα = 0.05.