The height of persons in a country is a random variable of the type

E(X−k)² is minimum when

Var(2X± 3) if Var(X)=1 is

For two random variables X and Y, the relation E(XY)=E(X)E(Y) holds good

If P₁ (x) and P₂ (x) be the marginal probability functions of two independent discrete random variables X and Y, then their joint probability function P(x,y)=

If P(A/B)=1/4 and P( B/A)=1/3, then P(A)/P(B) is equal to