Question

A set of data with a mean of 45 and a standard deviation of 8.3 is normally distributed. Find the value that is +3 standard deviations away from the mean.

a.69.9
b.48.0
c.78.9
d.20.1

Answer 1

\[\{45-3(8.3),45-3(8.3)\}\]
any number between this set

Answer 2

\[{45-3(8.3),45+3(8.3)}\]

Answer 3

\[45-3(8.3)\le x\le 45+3(8.3)\]
another way