9.4 9.9 9.9 9.9 10.0 10.2 10.2 10.5
The mean and the standard deviation of the 8 numbers shown are 10.0 and 0.3, respectively. What percent of the 8 numbers are within 1 standard deviation of the mean?
常搞不定 標準差和中位數的算法

(A) 90%
(B) 85%
(C) 80%
(D) 75%
(E) 70%
ANS :D