Advertisers need to know which age groups are likely to see their ads. Purchasers of 120 copies of Cosmopolitan are shown by age group.
(a) Make a bar chart and describe it.
(b) Calculate expected frequencies for each class.
(c) Perform the chi-square test for a uniform distribution. At α = .01, does this sample contradict the assumption that reader- ship is uniformly distributed among these six age groups? (See J. Paul Peter and Jerry C. Olson, Consumer Behavior and Marketing Strategy, 9th ed. [McGraw-Hill, 2004], p. 300.)

Purchaser Age Units Sold 18-24 25-34 35-44 45-54 55-64 65+ Total 381 28 19 16 10 120