The police department of a major city has found that the average height of their 1,250 officers is 71 inches ( u = 71 in.)

The police department of a major city has found that the average height of their 1,250 officers is 71 inches ( u = 71 in.) with sd = 2.3 inches. 

a. How many officers are at least 75 inches tall? 

b.What percent of officers are between 65 and 72 inches tall? 

c.The top 10% of the officers in terms of height also make higher salaries than the shorter officers. How tall does an officer have to be to get in that top 10% group? (I.e. what is the height marking off the top 10 percent?)