A die is thrown thrice. A success is 1 or 6 in a throw. Find the mean and variance of the number of successes.
Let p be the probability of success
∴ the p = probability of getting 1 or 6
Given, n = 3
Mean = np
= 1
Variance = npq
= 0.66
Therefore, mean = 1, standard deviation = 0.66.
15