Are Low-Fat Diets or Low-Carb Diets More Effective for Weight $\alpha = 0.05$

question 19

Short Answer

Are low-fat diets or low-carb diets more effective for weight loss? A sample of 70 subjects went on a low-carbohydrate diet for six months. At the end of that time, the sample mean weight loss was 10.5 pounds with a sample standard deviation of 7.09 pounds. A second sample of 76 subjects went on a low-fat diet. Their sample mean weight loss was 18.0 with a standard deviation of 7.26. Can you conclude that the mean weight loss differed between the two diets? Use the $\alpha = 0.05$ level.
i). State the appropriate null and alternate hypotheses.
ii). Compute the test statistic.
iii). How many degrees of freedom are there, using the simple method?
iv). Do you reject H₀ ? State a conclusion.