Carlos is analyzing the results of an experiment on two groups of mice in which he compared the difference in their weight gain after feeding each group a different type of food for one month. the difference in the mean weight gain is 0.6 grams. the standard deviation of the difference in sample means is 0.305.

Given:difference in the mean weight gain is 0.60 gramsstandard deviation of the difference in sample mean is 0.305
68% confidence interval for the population mean difference is a) 0.305
0.60 + 1 * 0.3050.60 + 0.305 = 0.9050.60 - 0.305 = 0.295
95% confidence interval for the population mean difference is c) 0.61
0.60 + 2 * 0.3050.60 + 0.61 = 1.210.60 - 0.61 = -0.01

The answer is 41.7 because 1.39 times 30 is 41.7