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 90% confidence interval for the difference 2 - , between in the mean recovery times for the two medications, assuming normal populations with equal variances. Medication 1 n, = 11 X1 = 14 $2 = 1.2 Medication 2 n2 = 19 X2 = 16 = 1.8 Click here to view nane 1 of the table of critical values of the t-distribution . . . The confidence interval is