A health club has sent promotional material to a mailing list consisting of local college students, area doctors, and lawyers. The accompanying table shows the record of individuals taking up the club's introductory offer in the first two weeks of the promotion. Frequency of Respondents Responded Students .08 Doctors .05 Lawyers .09 Total 22 Did Not Respond Total .16 24 .13 18 49 58 .78 1.00

a. What is the chance that a typical college student will respond to the promotion? A typical doctor? A typical lawyer? With respect to which group is the promotion most effective?

b. How might the information in the table be useful to marketing and advertising managers?