# Solving Probability using standard Deviation and Mean

Given a normal random variable with mean 90 and a standard deviation 3, find the probability that x is greater than or equal to 86.67 and less than or equal to 96.33

• Do you know how to normalise to standard normal distribution? – peterwhy Nov 18 '13 at 3:56

Hint: If $Y\text{~}N(\mu,\sigma^2)$, then $X=\frac{Y-\mu}{\sigma}\text{~}N(0,1)$.