Recovery time from surgery: A new postsurgical treatment is being compared with a standard treatment. Seven subjects receive the new treatment, while seven others (the controls) receive the standard treatment. The recovery times, in days, are given below.

Control: 18 23 24 30 32 35 39 Treatment: 12 13 15 19 20 21 24 Construct a 98% confidence interval for the reduction in the mean recovery times associated with treatment.