Write an exponential function to model the situation. Find each amount after the specified time. A population of 120,000 grows 1.2% per year for 15 years.

Exponential growth function is given by f (t) = A (1 + k%) ^t; where A is the initial value, k is the growth rate and t is the time period.

Therefore, the required function is

f (t) = 120,000 (1 + 0.012) ^t = 120,000 (1.012) ^t

After 15 years, the new population is 120,000 (1.012) ^15 = 120,000 x 1.1959 = 143,512