In the case of a discrete probability distribution of a random variable X, the mean is equal to the sum over every possible value weighted by the probability of that value; that is, it is computed by taking the product of each possible value x of X and its probability p(x), and then adding all these products together
To find the mean, you need to find the average. The equation that I used was 61(1)+64(3)+67(5)+70(6)+73(5) and then divided that total by the total number of 20.
