Power and Type II error (One population mean ) Sec 8.6: 95, 97, 99 Supplementary exercises 1- Power and Type II error (One population proportion ) 1. Let p denote the percentage that Arizona families open presents on Christmas Eve or Christmas day. To test H 0 : p = 0.5 vs. H a : p > 0.5, 144 Arizona families were surveyed and x, the number of families that open presents on Christmas Eve or Christmas day, was observed. (a) What is the rejection region for testing H 0 vs. H a at the 5% significance level? (Answer: to the right of 0.5685) (b) What is the power of this test when the true value of p is 0.65? (0.9798) (c) What is the probability of a Type II error when the true value of p is 0.6? (0.2206) 2. Let p denote the percentage of 18-25 years old people who were users of marijuana in 1995. To test H 0 : p = 10% vs. H a : p > 10%, 100 people in that age group were randomly selected, and x, the number of these who were current users of marijuana, was found. (a) What is the rejection region for testing H
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This note was uploaded on 09/10/2009 for the course STAT 217 taught by Professor Dan during the Winter '07 term at University of Calgary.