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 readership is uniformly distributed among these six age groups?
Purchaser Age Units Sold
18-24 38
25-34 28
35-44 19
45-54 16
55-64 10
65+ 9
Total 120