Marketing: Age What is the age distribution of promotion-sensitive shoppers? A supermarket super shopper is defined as a shopper for whom at least 70%

of the items purchased were on sale or purchased with a coupon. The following table is based on information taken from Trends in the United States (Food Marketing Institute, Washington, D.C.).

Age range, years 18–28 29–39 40–50 51–61 62 and over Midpoint x 23 34 45 56 67 Percent of super shoppers 7% 44% 24% 14% 11%

For the 62-and-over group, use the midpoint 67 years.

(a) Using the age midpoints x and the percentage of super shoppers, do we have a valid probability distribution? Explain.

(b) Use a histogram to graph the probability distribution of part (a).

(c) Compute the expected age m of a super shopper.

(d) Compute the standard deviation s for ages of super shoppers.

AppendixLO1