2. A study was conducted to see if an herbal supplement helped to reduce

weight. After 12 weeks, 42 subjects using the herbal supplement and a high-

fiber, low-calorie diet had a mean weight loss of 3.2 kg. And a standard

deviation of 3.3 kg. During the same period, 42 subjects using a placebo and a

high-fiber, low-calorie diet had a mean weight loss of 4.1 kg. And a standard

deviation of 3.9 kg.

Part 1.

At a=0.5, test the claim that the mean weight loss for the group using the the herbal supplement is greater than the mean weight loss for the group using the placebo.

a)

b)

c)

d)

e)

Part 2. Construct a 95% C. I. for mean differences.