you would need a calculator for it, unless you can do exponential math at such a degree... if you're using a PC there's a good graphing calculator at Desmos.com, it can show you how a graph looks, which shows that when n is 7, the answer is 364.5. also it wouldn't be 1093.5 because the exponent is n-1 which means that while n could be 7, you need to take away 1 before using it as an exponent.