Does Income Increase When You Get Married? to Investigate This,a

Multiple Choice

Does income increase when you get married? To investigate this,a college student has randomly selected people from his college town and collected income data for these people.They were categorized according to their marital status.The following results (in thousands of dollars) were obtained. The data are to be analyzed using the Wilcoxon rank sum test.Let W be the Wilcoxon rank sum test statistic equal to the sum of the ranks assigned to the married group.What is the expected value of W under the null hypothesis that the two distributions are the same?

A) 25
B) 27.5
C) 30
D) 55