question 11

Suppose that the lifetimes of tires of a certain brand are normally distributed with a mean of 75,000 miles and a standard deviation of (5 miles. These tires come with a 65,000mile warranty. The manufacturer of the tires can adjust a during the production process, but the adjustment ofo is quite costly. The manufacturer wants to set 0 once and for all so that only 10% of the tires will fail before warranty expires. Find the standard deviation to be set. Carry your intermediate computations to at least four decimal places. Round your answer to at least one decimal place. III miles X b I) units Suppose that the creatine kinase levels among healthy males are normally distributed with a standard deviation of 23 . Research shows that exactly 5% of umts the healthy males have a creatine kinase level above 151 T. What is the mean creatine kinase level in healthy males? Carry your intermediate computations to at least four decimal places. Round your answer to at least one decimal place. Suppose that the time required to complete a 1040R tax form is normal distributed with a mean of 90 minutes and a standard deviation of 10 minutes. What proportion of 1040R tax forms will be completed in at least 78 minutes? Round your answer to at least four decimal places. X 5 ?Seventy million pounds of trout are grown in the U.S. every year. Farmraised trout contain an average (mean) of 32 grams of fat per pound, with a standard deviation of 7.5 grams of fat per pound. A random sample of 35 farmraised trout is selected. The mean fat content for the sample is 30.7 grams per pound. Find the probability of observing a sample mean of 30.7 grams of fat per pound or less in a random sample of 35 farmraised trout. (Sam.r your intermediate computations to at least four decimal places. Round your answer to at least three decimal places. [D xo'? beats Suppose that pulse rates among healthy adults are normally distributed with a mean of 81 beats and a standard deviation of 8 minute . What proportion of minute beats healthy adults have pulse rates that are at least 65 ? Round your answer to at least four decimal places. minute X 5 ?The Credit Risk Department of a major bank estimates the default rate on loans under $10,000 to be 2%. A random sample of 1600 new loans that are under $10,000 is going to be selected. Let p be the proportion of defaults on the loans in the sample. Answer the following. (If necessary, consult a list of formulas.) (a) Find the mean of p. X 5 ? (b) Find the standard deviation of p. (c) Compute an approximation for P (p The Diversity, Equity, and Inclusion (DEI) office of a major multinational bank is investigating the process used to make recent hires for financial analysts. The office knows that exactly 12% of all applications were from minority candidates and that exactly 10% of the open positions were filled by members of a minority. For the investigation, the DEI office will take a random sample of 1650 applications. Let p be the proportion of minority applicants in the sample. Answer the following. (If necessary, consult a list of formulas.) (a) Find the mean of p. X ? (b) Find the standard deviation of p. (c) Compute an approximation for P (p