How do i find the answer to 0.008 is 1/10 of

On a string instrument, the length of a string varies inversely as the frequency of its vibrations. an 11-inch string has a frequency of 400 cylces per second. find the frequency of a 10-icnch string.

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?

Ineed with math stuff it involves graphs