Arithmetic mean and standard deviation of a certain normal distribution are 11.5 and 1.5. What value is exactly 2 standard deviations less than the mean?
Choices:
A) 10.5 B) 11 C) 11.5 D) 12 E) 8.5
The value which is exactly two SD below the mean is: mean-2*SD=11.5-2*1.5=8.5.   Answer: 8.5.
<result>E</result>
Arithmetic mean and standard deviation of a certain normal distribution are 11.5 and 1.5. What value is exactly 2 standard deviations less than the mean?