A certain set of test scores has an average (arithmetic mean) of 70 and a standard deviation of 25. If m and n, two numbers in the set, are both within 2 standard deviations from the average, then which of the following could be the average of m and n?
Pick:
A) 10  B) 14  C) 17  D) 19  E) 21
Given, mean = 70, SD = 25   Mean + 2(Standard Deviation) = 120   Mean - 2(Standard Deviation) = 20   m,n are both in this range i.e (20 to 120)   The least value that m,n take is 21 since m,n &gt; 20   m=n=21   Average of 2 numbers is 21   Answer: 21
<result>E</result>
A certain set of test scores has an average (arithmetic mean) of 70 and a standard deviation of 25. If m and n, two numbers in the set, are both within 2 standard deviations from the average, then which of the following could be the average of m and n?