Use "^" to show powers: P= 5000 e^(at)

Put in the values you are given: 1990- 1980= 10 so t= 10:Where t is in years and t = 0 corresponds to 1980. In 1990, the population was 10000. Find the value of the constant a and approx your answer to 3 dec places.

10000= 5000e^(10a)

Solve that for a. You will, of course, need to use the natural logarithm.