hw 7 having trouble

According to one study, brain weights of men are normally distributed with a mean of 1.30 kg and a standard deviation of 0. 15 kg. Use the data to answer a. Determine the sampling distribution of the sample mean for samples of size 3. The mean of the sample mean is ; = The standard deviation of the sample mean is of = (Round to four decimal places as needed.) b. Determine the sampling distribution of the sample mean for samples of size 12. The mean of the sample mean is - =. The standard deviation of the sample mean is of =