Q9. Ken Wallace is interested in testing whether the average price to earnings (P/E) of firms in the retail industry is 25. Using a t-distributed test statistic and a 5% level of significance, the critical values for a sample of 40 firms is/are: A) -1.96 and 1.96. B) -2.023 and 2.023. C) -1.685 and 1.685.
Q10 .Simone Mak is a television network advertising executive. One of her responsibilities is selling commercial spots for a successful weekly sitcom. If the average share of viewers for this season exceeds 8.5%, she can raise the advertising rates by 50% for the next season. The population of viewer shares is normally distributed. A sample of the past 18 episodes results in a mean share of 9.6% with a standard deviation of 10.0%. If Mak is willing to make a Type 1 error with a 5% probability, which of the following statements is most accurate?
A) With an unknown population variance and a small sample size, Mak cannot test a hypothesis based on her sample data. B) Mak cannot charge a higher rate next season for advertising spots based on this sample. C) The null hypothesis Mak needs to test is that the mean share of viewers is greater than 8.5%.
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发表于 2009-1-13 16:10
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