2.51 Heights For the sample heights of Georgia college students in Example 14, the males had xQ = 71 and s = 3, and the females had xQ = 65 and s = 3.

a. Use the empirical rule to describe the distribution of heights for males.

b. The standard deviation for the overall distribution (combining females and males) was 4. Why would you expect it to be larger than the standard deviations for the separate male and female height distributions? Would you expect the overall distribution still to be unimodal?