Consider an unfair coin that turns up heads one-fourth of the time. I toss the coin three times

Question

Consider an unfair coin that turns up heads one-fourth of the time. I toss the coin three times

and let X equal the number of heads. Find the probability distribution of X and then find its mean and variance. [ Hint: If X ∼Bin (n, p) then E(X) =np and Var(X) =np(1−p)]

Answer 1

mean = 3/4

variance = 9/16

it's a binomial distribution