Variance of random variable

Answer the following questions: If X is a discrete random variable, then define median of X.

If x is a discrete random variable and 'a' is a constant show that (i) E(a)=a (ii) E(ax)=aE(x) (iii) E(x-barX)=0

Define a discrete random variable X and its mean E(x) and variance Var(x)

Define the probability function of a discrete random variable x .state the conditions satisfied by it

Answer the following questions (Alternatives are to be noted): For a random variable X, show that [E (x^2)]^(1/2) ge E(x) .

A discreate random variable x has the following probability distribution: Find mean and standard deviation.

Let a pair of dice be thrown and the random variable X be the sum of the numbers that appear on the two dice. Find the mean or expectation of X.

1.choose the correct answer from the given alternatives:1. if X be the random variable of the no. of points obtained in a single throw of unbiased die , then the value of barX will be