What test statistic should you should use to test Ho versus H1? Select one: O a. Z X-Ho - N(0,1) O b. T= tn-1 O c. W = (n-1)8 Now suppose that n = 16, the observed sample mean ä is 8.9. the observed sample variance s² is 25 and 4o = 10.5. Suppose we next want to compute a 95% confidence interval for u. What is the lower endpoint of this 95% confidence interval? Give answer to three decimal places. What is the upper endpoint of this 95% confidence interval? Give answer to three decimal places.

The following data represent the length of time, in days, to recovery for patients randomly treated with one of two medications to clear up severe bladder infections. Find a 99% confidence interval for the difference µ, - H, between in the mean recovery times for the two medications, assuming normal populations with equal variances. Medication 1 n = = 10 x, = 17 = 1.9 Medication 2 n2 = 14 X2 = Click here to view page 1 of the table of critical values of the t-distribution. Click here to view page 2 of the table of critical values of the t-distribution. = 19 S2 = 1.5 .... . The confidence interval is