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...

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  μ2−μ1 between in the mean recovery times for the two​ medications, assuming normal populations with equal variances.