A Market Researcher Is Studying the Use of Coupons by Consumers

A market researcher is studying the use of coupons by consumers of varying ages.She classifies consumers into four age categories and counts the number of grocery store customers who use at least one coupon during check out.It is expected that data are uniformly distributed across the four age categories.The observed data results in frequencies of 22, 35, 32, and 21.Using $\alpha$ = .05, the observed chi-square value is _______.

A) 5.418
B) 9.10
C) 20.27
D) 4.51
E) 7.86