Question

If we increase our food intake, we generally gain weight. Nutrition scientists can calculate the amount of weight gain that would be associated with a given increase in calories. In one study, sixteen non-obese adults, aged 25 to 36 years, were fed 1,000 calories per day in excess of the calories needed to maintain a stable body weight. The subjects maintained this diet for 8 weeks, so they consumed a total of 56,000 extra calories. According to theory, 3,500 extra calories will translate into a weight gain of one pound. Therefore, we expect each of these subjects to gain 56,000/3,500 = 16 pounds. Here are the weights before and after the 8-week period, expressed in kg.

Subject	1	2	3	4	5	6	7	8
Weight before:	55.7	54.9	59.6	62.3	74.2	75.6	70.7	53.3
Weight after:	61.7	58.8	66.0	66.2	79.0	82.3	74.3	59.3
Subject	9	10	11	12	13	14	15	16
Weight before:	73.3	63.4	68.1	73.7	91.7	55.9	61.7	57.8
Weight after:	79.1	66.0	73.4	76.9	93.1	63.0	68.2	60.3

a) For each subject, find the weight gain (or loss) by subtracting the weight before from the weight after.

b) Convert the “16 pounds” expectation to kg by dividing by the conversion factor of 2.2. Now state the null and alternative hypotheses for this matched pairs test.

c) Conduct the test and state your conclusions. Include a ?-value in your summary

Answer 1