Chi-square for independence of attributes.
Can people really make out their favourite brand of cola? Volunteers tasted Coca-Cola Classic, Pepsi, Diet Coke, and Diet Pepsi, with the results shown below. Research problem: At _ = .05, is the correctness of the prediction different for the two types of cola drinkers? Could you recognize your favourite brand in this kind of test? Since it is a 2 _ 2 table, try also a two-tailed two-sample z test for ð1 = ð2 and confirm that z2 is the same as your chi-square statistic. Which test do you prefer? Why?
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Correct?
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Regular Cola
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Diet Cola
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Row Total
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Yes, got it right
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7
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7
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14
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No, got it wrong
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12
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20
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32
|
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Column Total
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19
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27
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46
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