From the tables below, find the mean and the variance.

From the table below, find the mean value and the variance.

From the tables below, calculate the mean and the variance.

Two numbers are selected at random (without replacement) from positive integers 2, 3, 4, 5, 6 and 7. Let X denote the larger of the two numbers obtained. Find the mean and variance of the probability distribution of X.

In a Binomial distribution, the sum of its mean and the variance is 1.8 . Find the probability of two successes, if the event was conducted 5 times.

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

There are 5 cards numbered 1 to 5, one number on one card. Two cards are drawn at random without replacement. Let X denotes the sum of the numbers on two cards drawn. Find the mean and variance of X.