A simple random sample of 21 patients between the ages of 38 and 82 were given a combination of the drugs ezetimibe and simvastatin. They achieved an average reduction of total cholesterol of 0.87 millimole per liter with a standard deviation of 0.17 millimole per liter. We are interested in the reduction of cholesterol. It has been confirmed that the random vairable comes from a normally distributed population. a) What parameter are we estimating? " 0' b) We can work this problem because: '/ 0' c) What is the point estimate of that parameter? _ 0" d) What is the standard deviation of the sampling distribution of the sample means? C] d) Find the margin of error for a 99% confidence interval for the true average cholesterol reduction. Use your T-table to do this and round to the fourth C] e) Round to the fourth. We are 99% confident that the true average reduction of cholesterol of those between the ages of 38 and 82 given the drugs ezetimibe and simvastatin is between C] and C]