And so this is a binomial random variable, or binomial variable, and we know the formulas for the mean and standard deviation of a binomial variable. So the mean, the mean of x, which is the same thing as the expected value of x, is going to be equal to the number of trials, n, times the probability of success on each trial, times p. So what is this going to be? Well, this is going to be equal to, we have 500 trials, and then the probability of success on each of these trials is 0.02. So it's 500 times 0.02. And what is this going to be? 500 times 2 hundredths is going to be, it's going to be equal to 10. So that is your expected value of the number of defective processing chips, or the mean.