Exam 18: Nonparametric Methods

Exhibit 18-6 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. -Refer to Exhibit 18-6. The mean and the standard deviation (respectively) for this test about the median are

Statistical methods that require assumptions about the population are known as

Excel's ____ function can be used to conduct the Kruskal-Wallis test.

Exhibit 18-3 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 below. -Refer to Exhibit 18-3. To test the null hypothesis, the appropriate probability distribution to use is

Exhibit 18-5 Forty-one individuals from a sample of 60 indicated they oppose legalized abortion. We are interested in determining whether or not there is a significant difference between the proportions of opponents and proponents of legalized abortion. -Refer to Exhibit 18-5. $\sigma$ in this problem is

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.

The level of measurement that allows for the rank ordering of data items is

Exhibit 18-5 Forty-one individuals from a sample of 60 indicated they oppose legalized abortion. We are interested in determining whether or not there is a significant difference between the proportions of opponents and proponents of legalized abortion. -Refer to Exhibit 18-5. The hypothesis is to be tested at the 5% level. The decision rule is not to reject the null hypothesis if

Exhibit 18-4 It has been hypothesized that there is no difference in the mathematical accuracy of men and women. A sample of men and women were given math tests. The scores on the tests are given below. -Refer to Exhibit 18-4. The test statistic equals (using the women as population 1)

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 the .05 level of significance.

Exhibit 18-5 Forty-one individuals from a sample of 60 indicated they oppose legalized abortion. We are interested in determining whether or not there is a significant difference between the proportions of opponents and proponents of legalized abortion. -Refer to Exhibit 18-5. The null hypothesis that is being tested is

A market research firm is conducting a study to determine which of two package designs for a liquid soap product potential customers prefer, the current design (A) or a new design (B). A sample of 20 potential customers is taken. The results follow. Use Excel to conduct the appropriate hypothesis test at $\alpha$ = .05 to determine if the data indicate that there is a difference in preference between the two designs.

The manager of a company believes that differences in sales performance depend 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.Test the null hypothesis at the 5% level.

The Spearman rank-correlation coefficient is

Two individuals were asked to rank the performances of eight different automobiles. The following show their rankings. Determine the Spearman rank-correlation coefficient and test for a significant correlation with $\alpha$ = 0.05.

If the assumption can be made that the populations all have the same shape, the Kruskal-Wallis test becomes

Exhibit 18-5 Forty-one individuals from a sample of 60 indicated they oppose legalized abortion. We are interested in determining whether or not there is a significant difference between the proportions of opponents and proponents of legalized abortion. -Refer to Exhibit 18-5. The conclusion is that there

Ten administrative assistants were sent to take a typing efficiency course. The following data show the typing speeds of the administrative assistants before and after the course. At $\alpha$ = 0.05, what can be concluded about the effectiveness of the course?

Two movie critics have independently ranked the top 20 movies of the year. Their rankings follow. Use Excel to calculate the Spearman correlation coefficient and then interpret its value.

Independent random samples of ten day students and ten evening students at a university showed the following age distributions. Use $\alpha$ = 0.05 and test for any significant differences in the age distribution of the two populations.