Let X denote the sum of the numbers obtained when two fair dice are rolled. Find the variance and standard deviation of X.

The expected value of the sum of the two numbers obtained when two fair dice are rolled is

Find the variance and standard deviation for the following data:

Two numbers are selected at random (without replacement) from first six positive integers. Let X denote the larger of the two numbers obtained. Find the probability distribution of X. Find the mean and variance of this distribution.

There are 4 cards numbered 1, 3, 5 and 7, one number on one card. Two cards are drawn at random without replacement. Let 'X' denote the sum of the numbers on the two drawn cards. Find the mean and variance of X.

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 .

Two numbers are selected are 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.

Find the mean,variance and standard deviation of first n natural numbers.