M is a certain set of numbers with an average (arithmetic mean) of 10 and a standard deviation of 1.5. Q is a subset of M consisting of 5 terms. Exactly 80% of the numbers in Q are located within 2 standard deviations from the average of M. Which of the following could Q be? Select.
A) {3, 4, 5, 10, 14}
B) {3, 7, 7, 10, 12}
C) {3, 5, 5, 10, 16}
D) {1, 5, 7, 10, 18}
E) {5, 6, 7, 10, 12}
Exactly 80% of the numbers in Q, so 4 out of 5 numbers are from 10 - 2*{SD} = 7 to 10 + 2*{SD} = 13.   A. {3, 4,5, 10, 14} --&gt; only 3 numbers are in this range. Discard.   B. {3,7, 7, 10, 12} --&gt; 4 numbers are in this range. OK.   C. {3,5, 5, 10, 16} --&gt; only 1 number is in this range. Discard.   D. {1,5, 7, 10, 18} --&gt; only 2 numbers are in this range. Discard.   E. {5, 6, 7, 10, 12} --&gt; only 3 numbers are in this range. Discard.   Answer: {3, 7, 7, 10, 12}.
<result>B</result>
M is a certain set of numbers with an average (arithmetic mean) of 10 and a standard deviation of 1.5. Q is a subset of M consisting of 5 terms. Exactly 80% of the numbers in Q are located within 2 standard deviations from the average of M. Which of the following could Q be?