To estimate the mean height u of male student on your campus, you will measure an SRS of students. Heights of people of the same sex and similar ages are close to Normal. You know from govt data that the standard deviation of the heights of young men is about 2.8 inches. suppose (unknown to you) the mean height of all male students is 70 inches. you measure 25 students. what is the sampling distribution of their average height x bar?