A fair coin is tossed $100$ times, and $X$ is the number of heads. A student uses the normal approximation with a continuity correction to estimate $P(X \le 45)$. A table gives $\Phi(0.8) = 0.7881$, $\Phi(0.9) = 0.8159$, $\Phi(1.0) = 0.8413$ and $\Phi(1.1) = 0.8643$. Which value does she get?