QUESTION THREE

Suppose the force acting on a column that helps to support a building is normally distributed with mean $15\mathrm{.}0$ kips and standard deviation $1\mathrm{.}25$ kips. What is the probability that the force

$($a$)$ Is between $10$ and $12$ kips?

$($b$)$ Differs from $15\mathrm{.}0$ kips by at most $2$ standard deviations?