So if in 2000, the town at 3901 people, with a decrease of 1.8%, and you want to find the population at 2013, first you want to set up your equation.
3901(1-0.018)^13
the first number being your total population, the inside number being the amount of decrease(make sure its -0.018, if you put a + you would calculate an increase at a rate of 1.8%.) the ^13 is the time, which is 13 years.
Your answer is 3081. Rounded up to a whole number because you cant have a sixth of a person.
Hope this helped
