Now, we have seen random variables like this before. This is a binomial random variable. Now, what do we know about its mean and standard deviation? Well, in previous videos, we know that the mean of this binomial random variable is just going to be equal to N times the mean of each of the Bernoulli trials right over here. So N times P, which in this particular situation is going to be, N is 10, we're doing 10 trials, and P is 0.6, which is equal to six. And that makes sense. If 60% of the balls here are yellow, and if you were to take a sample, or if you were to take 10 trials, so if you were to take 10 balls one at a time, they have to be independent, so you keep looking at them and then replacing them, but if you took 10, then you would expect that six of them would be yellow.