Set R has a mean of 9 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?	Pick:
A) {18, 20}  B) {8, 10}  C) {28, 38}  D) {6, 10}  E) {5, 10}
The lesser the variance( values closer to mean) ,lower the standard deviation. As discussed in question the mean is 9,the values (8,10) are closer than others.   Hence Answer : {8, 10}
<result>B</result>
Set R has a mean of 9 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?