 Hi and welcome to the session. Let's work out the following question. The question says a coin is tossed four times. Find the mean and variance of the probability distribution of the number of heads. So let us see the solution to this question. Let P denote the probability of getting head in a single toss of a coin P is equal to 1 by 2 and Q is also equal to 1 by 2. Now here N is equal to 4, therefore mean that is equal to N into P is equal to 4 into 1 by 2 that is equal to 2. And variance that is N P Q is equal to 4 into 1 by 2 into 1 by 2 that is equal to 1. So our answer to this question is that mean is equal to 2 and variance is equal to 1. This is our answer to this question. I hope that you understood the solution and enjoyed the session. Have a good day.