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. Now what about the standard deviation? So the standard deviation of our random variable, x, well that's just going to be equal to the square root of the variance of our random variable, x. So I could just write it, I'm just writing it all the different ways that you might see it, because sometimes the notation is the most confusing part in statistics.