Reference no: EM132372888

According to an April 28, 2015, report on the website newsroom.aaa.com, the average cost of owning and operating a sedan automobile in the United States in 2015 was $8,968. Suppose the California AAA plans to conduct a survey to determine whether the average cost of owning a sedan in California is less than the $8,968 for the nation as a whole. Assuming that the population standard deviation for the cost of owning a sedan is $750, what is the probability that the hypothesis test will lead to accepting the null hypothesis if the true mean cost in California is actually $8,700.

1. State the null and alternative hypotheses.
2. Calculate the probability of a Type II error. Assume that the test is to be conducted using an alpha level of 0.01 and a sample size of 100 sedan owners.

Suppose a project was undertaken by the Department of Labor in a southern state to determine whether the most recent economic recession affected men and women differently. Assume that random samples of 485 adult males and 242 adult females were selected. The subjects were asked whether they had been involuntarily unemployed for four or more consecutive weeks at any time during the past 8 years. Fifty of the men responded "Yes" to the question, and 36 women responded "Yes." Based on these sample data, what should the analysis by the Department of Labor conclude about whether there is a statistical difference in the proportions of men and women who were unemployed? Test at an alpha = 0.05 level.