Question

Given that X ~ B(n, p), if n = 10 and p = 0.4, find E(X) and Var(X)

Answer 1

X ~ B(n, p)

Here, n = 10, p = 0.4

∴ q = 1 – p = 1 – 0.4 = 0.6

E(X) = np = 10 × 0.4 = 4

Var(X) = npq = 10 × 0.4 × 0.6 = 2.4