Find the probability distribution of the number of doublets in four throws of a pair of dice. Also find the mean and variance of this distribution.

Find the probability distribution of the number of doublets in 4 throws of a pair of dice. Also, find the mean and variance of this distribution.

Find the probability distribution of number of doublets in three throws of a pair of dice.

Find the probability distribution of number of doublets m three throws of a pair of dice.

From a lot of 30 bulbs, which include 6 defectives, a sample of 4 bulbs is drawn at random with replacement. Find the probability distribution of the number of defective bulbs. Also find the mean and variance of the distribution.

Out of a group of 30 honest people, 20 always speak the truth. Two persons are selected at random from the group. Find the probability distribution of the number of selected persons who speak the truth. Also find the mean of the distribution

Find the probability distribution of the random variable x,which denotes the number of doublets in four throws of a pair of dice.Hence,find the mean of the number of doublets (X).

An urn contains 3 white and 6 red balls. Four balls are drawn one by one with replacement from the urn. Find the probability distribution of the number of red balls drawn. Also find mean and variance of the distribution.

Five bad oranges are accidently mixed with 20 good ones. If four oranges are drawn one by one successively with replacement, then find the probability distribution of number of bad oranges drawn. Hence find the mean and variance of the distribution.

is the probability distribution of a random variable X. Find the variance of X.

is the probability distribution of a random variable X. Find the variance of X.