The probability that any given tennis set will go to a tiebr

The probability that any given tennis set will go to a tiebreaker is 13%. If I randomly select 260 tennis sets, with the random variable X being the number of tiebreakers, what is the mean of X? _____ What is the standard deviation of X? ______

Solution

p =Prob that any given set will go to tiebreaker = 0.13

n =260

This is binomial with n =260 p =0.13

Mean =260(0.13) = 33.80

Variance =npq = 29.406

std dev = 5.423