Answer Happy

-- A beauty company wants to determine if their low-fat diet or their low-carbohydrate diet is more effective. A sample of nx 14 subjects went on their low-fat diet for one year. At the end of that time the sample mean weight loss was i 3.2 kg with a sample standard deviation of SX 2.2 kg. A second sample of ny 12 subjects went on their low-carbohydrate diet. Their sample mean weight loss was y = 2.7 kg with a sample standard deviation of sy = 1.2 kg. Page 1 of 2 (a) (10 marks) Assume that the effectiveness of the two diets are independent and approximately normally distributed with unknown but equal variance. Find an 80% confidence interval on the difference in mean weight loss lix - HY. (b) (10 marks) Assume that the effectiveness of the two diets are independent and approximately normally distributed with unknown and unequal variance. Test whether their low-fat diet and their low-carbohydrate diet have equal effectiveness at 0.1 significance level.