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The American Bankers Association collects data on the use of cards, personal che

ID: 3250095 • Letter: T

Question


The American Bankers Association collects data on the use of cards, personal checks, and cash when consumers pay for in-store purchase. In usages were reported. a = 0.05. A sample taken in 2003 found that for 100 in-store purchases, 36 used a debit card, 23 used a personal check, and 24 used cash. The researchers are a change occurred in how customers paid for in-store purchase. (a) State the null hypothesis and alternative hypothesis. (b) Compute the test statistic. (c) What is the critical value? What is your conclusion for this test?

Explanation / Answer

a)

H0: The customers paid for in-store purchase are consistent with a specified distribution.

Ha: The customers paid for in-store purchase are not consistent with a specified distribution.

b) Consider the following table:

Test statistic, ²= (O-E)²/E = 16.829

c) df=k-1=4-1=3

Critical value at =0.05, is 7.815.

Since ² = 16.829 > 7.815, reject null hypothesis. There is sufficient evidence to conclude that the customers paid for in-store purchase has changed.

In-Store purchase Percentage(p) O E=N*p (O-E)²/E Credit Card 22% 36 22 8.909 Debit Card 21% 17 21 0.762 Personal check 18% 23 18 1.389 Cash 39% 24 39 5.769 Total 1 N=100 100 16.829