Interpreting a Computer Display A U.S. Department of Justice report (NCJ-156831)

included the claim that “in spouse murder cases, wife defendants were less likely to be convicted than husband defendants.” Sample data consisted of 277 convictions among 318 husband defendants, and 155 convictions among 222 wife defendants.

Test the stated claim and identify one possible explanation for the result. The Minitab results are shown here.

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448 CHAPTER 8 Inferences from Two Samples TI-83 Plus Sample X N Sample p 1 277 318 0.871069 2 155 222 0.698198 Estimate for p(1) 2 p(2): 0.172871 95% lower bound for p(1) 2 p(2): 0.113511 Test for p(1) 2 p(2) 5 0 (vs . 0): Z 5 4.94 P-value 5 0.000