Question

In 1985, there was 285 cell phones subscribers in the small town of centerville.After 1985, the number of subscribers increased by 75% per year. How many cell phones subscribers were in centerville in 1994 ?

Answer 1

First we write a function that suits the problem.
We have then:
y = 285 * (1.75) ^ x
Then, we see how many years there are in the requested period
x = 1994-1985 = 9
We evaluate the function for x = 9
y = 285 * (1.75) ^ 9
y = 43871.98637
Round nearest whole number
y = 43872
Answer:
there were 43872 cell phones subscribers in centerville in 1994