The president of a large company is in the process of deciding whether to adopt a lunch-time exercise program. The purpose of such programs is to improve the health of workers and, in so doing, reduce medical expenses. To get more information, he instituted an exercise program for the employees in one office. The president knows that during the winter months medical expenses are relatively high because of the incidence of colds and flu. Consequently, he decides to use a matched pairs design by recording medical expenses for the 12 months before the program and for 12 months after the program. The "before" and "after" expenses (in thousands of dollars) are compared on a month-to-month basis. Use the following Excel output to test the claim that the exercise programs reduce medical expenses, at 5% level of significance.

Month Before Program After Program Jan 68 59 Feb 44 42 Mar 30 20 Apr 58 62 May 35 25 Jun 33 30 Jul 52 56 Aug 69 62 Sep 23 25 Oct 69 75 Nov 48 40 Dec 80 46