So they don't want us to actually answer the question, they just want us to set up the expression using some symbols from calculus. So why don't you pause this video and try to think about it. So let's just remind us what they've given us. They've given us the rate function right over here. And so if you want to find a change in population from one time to another time, what you could do is you could take the integral of the rate function from the starting time, t is equal to two years, to t is equal to seven years. So we're gonna take the integral of the rate function, and what this is going to tell us, this is going to tell us the change in population from time two to time seven. So this is, you could say, let me just write this, this is the change, I'll use delta for change, or let me just write it out.