According to a Nielsen report, the average age of an audience watching American Idol Season 8 was 39.3 years with σ = 6 years. A random sample of 100 audiences for the Season 9 show yielded a mean age of 41.2 years. At the 5% significance level, do the data provide sufficient evidence to conclude that the population mean age of audience members for American Idol has increased? (hint: Conduct a Hypothesis Test)

A manager of a company believes that the average age of its customers is 40. However, theCEO of the company thinks that the average age of the company’s customers differs from 40. To testthis, she randomly selected 60 customers, and the average customer age was found to be 42.7 years.Assume the (population) standard deviation for customer age is 8 years. Using a 5% level ofsignificance, does the sample provide enough evidence to refute the claim made by the manager

The professior of a university believes that the average age of the bachelor students  is 23. However, the tutor belives that the average age of the bachelor students differs from 23. To test the claim, they randomly selected 100 students, the average age was found to be 24.2 years. Assume the population standard deviation for the student age is 6 years. At the 1% level of significance, what is the test statistics?

Use the following information to answer the question. The mean age of lead actresses from the top ten grossing movies of 2010 was 29.6 years with a standard deviation of 6.35 years. Assume the distribution of the actresses' ages is approximately unimodal and symmetric Between what two values would you expect to find about 68% of the lead actresses ages?

The mean winter temperature in San Francisco for the month of December is 48°F. Suppose a random sample of 15 days in December showed a sample mean of 46.2°F. Assume that σ = 3 and a normally distributed population. At the 5% significance level, do the data provide sufficient evidence to conclude that the population mean is less than 48°F? (hint: Conduct a Hypothesis Test)

A study was conducted to estimate μ, the mean number of weekly hours that U.S. adults use computers at home. Suppose a random sample of 81 U.S. adults gives a mean weekly computer usage time of 8.5 hours and that from prior studies, the population standard deviation is assumed to be σ = 3.6 hours.A similar study conducted a year earlier estimated that μ, the mean number of weekly hours that U.S. adults use computers at home, was 8 hours. We would like to test (at the usual significance level of 5%) whether the current study provides significant evidence that this mean has changed since the previous year.Using a 95% confidence interval of (7.7, 9.3), which of the following is an appropriate conclusion? The current study does provide significant evidence that the mean number of weekly hours has changed over the past year, since 8 falls outside the confidence interval. The current study does not provide significant evidence that the mean number of weekly hours has changed over the past year, since 8 falls outside the confidence interval. The current study does provide significant evidence that the mean number of weekly hours has changed over the past year, since 8 falls inside the confidence interval. The current study does not provide significant evidence that the mean number of weekly hours has changed over the past year, since 8 falls inside the confidence interval. You cannot draw a conclusion because the only way to reach a conclusion is to find the p-value of the test.