Chisquare test for Goodness of fit.
Advertisers need to know which age groups are probable to see their ads. Purchasers of 120 copies of Cosmopolitan are shown by age group. (a) Make a bar chart and describe it. (b) find out expected frequencies for each class. (c) Perform the chisquare test for a uniform distribution. At α = .01, does this sample contradict the assumption that readership is uniformly distributed among these six age groups? (See J. Paul Peter and Jerry C. Olson, Consumer Behaviour and Marketing.
Strategy, 9th ed. [McGrawHill, 2004], p. 300.) Cosmo
Purchase Age

Units Sold

18  24

38

25  34

28

35  44

19

45  54

16

55  64

10

65 +

9

Total

120

(a) Build a bar chart and describe it.
(b) Compute expected frequencies for each class.
(c) Execute the chisquare test for a uniform distribution. At α = .01, does this sample contradict the assumption that readership is uniformly distributed?