Proofs for the Expectation and Variance (VCE SSCE Mathematical Methods): Flashcards

$E(X) = np$

$Var(X) = np(1-p)$

Probs sum to 1, $E(X)=np$, $Var(X)=np(1-p)$

(a+b)^n = sum_{k=0}^{n} inom{n}{k} a^{n-k} b^k

1

1

$Var(X) = E(X^2) - mu^2$

Find $E[X(X-1)]$ first

$n(n-1)p^2$

$0.5$