The director for Weight Watchers International wants to determine if the changes in their program results in better weight loss. She selected 25 Weight Watcher members at random and compared their weight 6 months later to weight at the start of the program. The results are in this excel file: attached

(The weight in the column labeled "After" represents their weights six months later and "Before" represents their weight at the start of the six-month period.) The director used .05 as the significance level.

Use Excel to test. For each paired difference, compute After - Before. In Data Analysis, t-Test: Paired Two Sample for means, select the After data for Variable 1 Range. Note that the critical value output by Data Analysis for this test is always positive. In this problem, the sign of the critical value is negative corresponding to a 1-tailed test with lower reject region and a negative lower critical value.

What are the Null and Alternate Hypotheses?

Person	Before	After	LBS Lost
1	176	164	12
2	192	191	1
3	185	176	9
4	177	176	1
5	196	185	11
6	178	169	9
7	196	196	0
8	181	172	9
9	158	158	0
10	201	193	8
11	191	185	6
12	193	189	4
13	176	175	1
14	212	210	2
15	177	173	4
16	183	180	3
17	210	204	6
18	198	192	6
19	157	152	5
20	213	200	13
21	161	161	0
22	177	166	11
23	210	203	7
24	192	186	6
25	178	170	8