So like always, try to pause this video and have a go at it on your own, and then we will work through it together. All right, so let me define a random variable that we're gonna find the mean and standard deviation of. And I'm gonna make that random variable the number of defective processing chips in a 500-chip sample. So let's let X be equal to the number of defective chips in 500-chip sample. So the first thing to recognize is that this will be a binomial variable. This is binomial. How do we know it's binomial?