Beer and Diapers: There is a popular story(among data miners) that there is a correlation between men buyingdiapers and buying beer while shopping. A student tests this theoryby surveying 160 male shoppers as they left a grocery store. Theresults are summarized in the contingency table below.
Observed Frequencies: Oi's
| Bought  |   DidNot  | |
|   Diapers  |   BuyDiapers  |   Totals  |
| Beer  |   8  |   21  |   29  |
| No Beer  |   10  |   121  |   131  |
| Totals  |   18  |   142  |   160  |
The Test: Test for a dependent relationshipbetween buying beer and buying diapers. Conduct this test at the0.01 significance level.
(a) What is the test statistic? Round your answer to 3decimal places.
χ2
=
(b) What is the conclusion regarding the null hypothesis?
reject H0fail to rejectH0Â Â Â Â
(c) Choose the appropriate concluding statement.
The evidence suggests that all men who buy diapers also buybeer.The evidence suggests that the probability of a man buyingbeer is dependent upon whether or not he buysdiapers.     There is not enough evidenceto conclude that the probability of a man buying beer is dependentupon whether or not he buys diapers.We have proven that buying beerand buying diapers are independent variables.
