The arithmetic mean and standard deviation of a certain normal distribution are 16.5 and 1.5, respectively. What value is exactly 2 standard deviations less than the mean?
Pick
A) 10.5	B) 11	C) 11.5	D) 12	E) 13.5

Rationale: "the value which isexactlytwo sd less than the mean is : mean - 2 * sd = 16.5 - 2 * 1.5 = 13.5 . answer : e ."
Answer: E