What does the 8.7% tax mean? what is it in dollars?

Any is very appreciated! (picture is provided below)not sure how to do this at all won't lie

Is the product of two rational numbers irrational or rational? first, make a hypothesis by multiplying two rational numbers. then, use variables such as x=a/b and y=c/d and the closure property of integers to prove your hypothesis.

The function f(x) = 14,600(1.1)* represents the population of a town x years after it was established. what was the original population of the town?