Juan -The population is declining by 3% every year, so let's try to put that into an equation. First, you should always convert percent to decimal. 3% is the same as 0.03 in decimal, agree?Second, when you see "declining" you should think of subtraction. If you have a dollar and it declined by .03, you would have 0.97 left, right? So, think of an exponential function y = P(0.97)^(t), where t = the time in years since 1950 and P is the initial population.The function then is:y = 250000 * (0.97)^(t)Hope this helped