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Question
Let X ~ B(n, p). If n = 10 and E(X) = 5, using the following activity find p and Var(X)
Solution: E(X) = `square = 5 square "p" = square, "q" = square`
Var(X) = `square`
Solution
E(X) = np= 5
∴ 10p = 5
p = `1/2`, q = `1/2`
Var(X) = npq
= `10 xx 1/2xx 1/2`
= 25
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