Amarket research group is interested in comparing the mean weight loss for two different popular diets. the researcher chooses two random samples of participants for the two diet programs. for diet a, the mean weekly weight loss for 10 participants was 1.5 pounds with standard deviation 0.4 pounds. for diet b, the mean weekly weight loss for 12 participants was 1.2 pounds with standard deviation 0.6 pounds. at a 5% significance level, does this indicate that diet a is better than diet b?