Answer
$P(x < 100) = 0.0918$
Work Step by Step
$\mu$ = 138.5, $\sigma$ = 29
Want to find $P( x <100 )$
i) Convert 100 to a z-score:
z = $\frac{x - \mu}{\sigma}$
z = $\frac{100 - 138.5}{29}$
z= -1.33
ii) $P(x < 100) = P(z < -1.33) = 0.0918$
