Set S has a mean of 10 and a standard deviation of 1.5. We are going to add two additional numbers to Set S. Which pair of numbers would decrease the standard deviation the most?  Choose the correct choice from the following choices:
A) {2, 10} B) {9, 11} C) {10, 18} D) {7, 13} E) {16, 16}
answer B,C, and E mean is not 10 therefore not accepted . D mean is 10 but S.D is more. therefore accepted   answer is B mean is 10 and S.D decreases minimum.   {9, 11}
<result>B</result>
Set S has a mean of 10 and a standard deviation of 1.5. We are going to add two additional numbers to Set S. Which pair of numbers would decrease the standard deviation the most?