The number of people who voted follows a binomial distribution with probability of having voted \(p=0.22\) and \(n=150\) subjects, which means the approximating normal distribution should have mean \(np=33\) and standard deviation \(\sqrt{np(1-p)}\approx5.07\).
With the continuity correction, you have
\(\mathbb P(X<39)\approx\mathbb P(X<38.5)=\mathbb P\left(\dfrac{X-33}{5.07}<\dfrac{38.5-33}{5.07}\right)=\mathbb P(Z<1.08)\approx0.86\)
