Answer : 29.8
A set of data with a mean of 40 and a standard deviation of 5.1 is normally distributed.
Mean = 40
standard deviation = 5.1
Find the value that is −2 standard deviations from the mean.
standard deviation = 5.1
-2 standard deviation =

The value that is −2 standard deviations from the mean = 40 - 10.2
= 29.8