Following are four variables for 30 cases from the General Social Survey. Age is reported in years. The variable happiness consists of answers to the question "Taken all together, would you say that you are (1) very happy (2) pretty happy, or (3) not too happy?" Respondents were asked how many sex partners they had over the past five years. Responses were measured on the following scale: 0-4 = actual numbers; 5= 5-10 partners; 6 = 11-20 partners; 7 = 21-100 partners; 8 = more than 100.

a. For each variable, find the appropriate measure of central tendency and '"write a" sentence reporting this statistical information as you would in a research report.

b. For the variable age, construct a frequency distribution with interval size equal to 5 and the first interval set at 20-24. Compute the mean and median for the grouped data and compare with the values computed for the ungrouped data. How accurate are the estimates based on the grouped data?