Let's first find the equation to find what the population went up to. X, will be the population of last year.
1.15x=76,894
Now, we need x by itself, so we need to divide both sides by 1.15.
76,894÷1.15≈66,864
There are decimals, but for this problem, hae .3478 of a person would not fit.
We can check our answer.
66,864×.15=10,029.6
10,029.6+66,864=76,893.6 (rounds up to 76,864)
So the population of the town last year was about 66,864 (66,864.3478) people.