Exam 18: Nonparametric Methods

It has been hypothesized that there is no difference in the mathematical ability of men and women. To test this hypothesis, decision was taken to use the Mann-Whitney-Wilcoxon test. A sample of men and women were given math tests. The scores on the tests are given below. ​ The standard deviation (σW) is

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 17 students (6 majoring in accounting, 6 majoring in management, and 5 majoring in marketing). ​ At α = .05, test to see if there is a significant difference in the performance of the students in the three majors.

Nonparametric methods are statistical methods that

Students in statistics classes were asked whether they preferred a 10-minute break or to allow them go out of class 10 minutes early. In a sample of 150 students, 40 preferred a 10-minute break, 80 preferred going out 10 minutes early, and 30 had no preference. We want to determine if there is a difference in students' preferences. At the 1% level of significance, the null hypothesis should

Two faculty members (X and Y) ranked five candidates for scholarships based on performance in sports and after-school activities. The rankings are shown below. ​ Compute the Spearman rank-correlation coefficient.

It is believed that the median yearly income in a suburb of Atlanta is $70,000. A sample of 67 residents was taken. Thirty-eight had yearly incomes above $70,000, 26 had yearly incomes below $70,000, and 3 had yearly incomes equal to $70,000. The null hypothesis to be tested is H₀: Median = $70,000. The mean and the standard deviation (respectively) for this test about the median are

A clothing manufacturer purchased some newly designed sewing machines in the hopes that production would be increased. The production records (in units/week) 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 .10 level of significance.

A nonparametric test for the equivalence of two populations would be used instead of a parametric test for the equivalence of the population parameters if

Fifteen people were asked to indicate their preference for domestic versus imported cars. The following data showed their preferences. ​ With α = .05, test for a significant difference in the preferences for cars. A "+" indicates a preference for imported cars.

Nonparametric methods which can be used to make inferences about a population without requiring an assumption about the distribution of the population are also called​

A company advertises that food preparation time can be significantly reduced with the Handy Dandy Slicer. A sample of 12 individuals prepared the ingredients for a meal with and without the slicer. You are given the preparation times (in minutes) below. ​ The p-value for this test is

Students in statistics classes were asked whether they preferred a 10-minute break or to allow them go out of class 10 minutes early. In a sample of 150 students, 40 preferred a 10-minute break, 80 preferred going out 10 minutes early, and 30 had no preference. We want to determine if there is a difference in students' preferences. The null hypothesis that is being tested is

Test scores of ten individuals before and after a training program are shown below. ​ At α = .05, what can be concluded about the effectiveness of the training program?

A sign test is a

Students in statistics classes were asked whether they preferred a 10-minute break or to allow them go out of class 10 minutes early. In a sample of 150 students, 40 preferred a 10-minute break, 80 preferred going out 10 minutes early, and 30 had no preference. We want to determine if there is a difference in students' preferences. To test the null hypothesis, the appropriate probability distribution to use is

The level of measurement that is simply a label for the purpose of identifying an item which can be used in nonparametric procedures is _____ measurement.

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 .05 level of significance, determine if there is evidence of a significant difference in the preferences for the two makes of automobiles. Hint: Use the continuity correction factor.

It is believed that the median yearly income in a suburb of Atlanta is $70,000. A sample of 67 residents was taken. Thirty-eight had yearly incomes above $70,000, 26 had yearly incomes below $70,000, and 3 had yearly incomes equal to $70,000. The null hypothesis to be tested is H₀: Median = $70,000. To test the null hypothesis, the appropriate probability distribution to use is