Related questions with answers

$The~ Cincinnati~ Enquirer$ reported that, in the United States, $66\%$ of adults and $87\%$ of youths ages $12$ to $17$ use the Internet ( $The ~Cincinnati~ Enquirer$ , February $7,~ 2006$ ). Use the reported numbers as the population proportions and assume that samples of $300$ adults and $300$ youths will be used to learn about attitudes toward Internet security.

Show the sampling distribution of $\bar{p}$ where $\bar{p}$ is the sample proportion of adults using the Internet.

A recent article in the Cincinnati Enquirer reported that the mean labor cost to repair a heat pump is $90 with a standard deviation of$22. Monte’s Plumbing and Heating Service completed repairs on two heat pumps this morning. The labor cost for the first was $75 and it was$100 for the second. Assume the distribution of labor costs follows the normal probability distribution. Compute z values for each and comment on your findings.

According to the South Dakota Department of Health, the mean number of hours of TV viewing per week is higher among adult women than men. A recent study showed women spent an average of 34 hours per week watching TV and men 29 hours per week. Assume that the distribution of hours watched follows the normal distribution for both groups, and that the standard deviation among the women is 4.5 hours and is 5.1 hours for the men. a. What percent of the women watch TV less than 40 hours per week? b. What percent of the men watch TV more than 25 hours per week? c. How many hours of TV do the one percent of women who watch the most TV per week watch? Find the comparable value for the men.