Hey I'm having trouble with trying to figure these two problems out:

Let f(x) = cx^3.31. How do the function values f(3.6) and f(5.5) compare?

Let f(x) = cx^4.2 and suppose that f(4) = 18. Find the value of c.

I've tried plugging them all in and subtracting but i can't seem to figure it out