aez-notes

When 100 coins are tossed, what is the probability that exactly 50 are heads?

This is just evaluating the binomial PMF, but we can also do it using the normal approximation since this the distribution is approximately normal.

load(distrib);

pdf_binomial(50, 100, 0.5), numer;
pdf_normal(50, 50, sqrt(25)), numer;
/* approx 0.080 */