Carcass wrote:
Set T consists of five integers: the first five odd prime numbers when counting upward from zero. This gives set T a standard deviation of approximately 3.71. Which of the following values, if added to the set T, would increase the standard deviation of set T?
A. 11
B. 9
C. 7.8
D. 4.15
E. 3.7
Let the first five odd prime numbers = 3 ,5 , 7 ,11 and 13
Now mean of these numbers = \(\frac{{3 + 5 + 7 + 11 + 13}}{5} = 7.8\)
So any value outside the range of (Mean - SD = 7.8 - 3.71 = 4.09) and (Mean + SD = 7.8 + 3.71 = 11.51) will increase the SD of the set
Only option E lies outside the range