If a certain sample of data has a mean of 15 and a standard deviation of 2, which of the following is not within 2 standard deviations?  Answers
A) 11 B) 15 C) 10 D) 12 E) 14
If a data distribution is normal then the 68% data values are within one standard deviation of the mean (i.e., μ ± σ), and about 95 percent are within two standard deviations (μ ± 2σ).   Here, mean = 15 and standard distribution is 2.   Numbers which are within two standard distribution will be in the range of 15±(2*2) i.e. 11 to 19.   Only only which does not follow this range is 10   Answer is 10
<result>C</result>
If a certain sample of data has a mean of 15 and a standard deviation of 2, which of the following is not within 2 standard deviations?