Answer
$121.29$
Work Step by Step
Given $\mu=115,\sigma=12$, assume the lowest
acceptable score that would enable a candidate to apply
for membership is $X_0$, we have $z=\frac{X_0-115}{12}$
Since $P(X\gt X_0)=1-P(z)=0.3$, we get $P(z)=0.7$ and use
table E or a calculator, we find $z=0.5244$, thus $\frac{X_0-115}{12}=0.5244$
and $X_0=121.29$
