I think I'm meant to "see" a Riemann Sum in there somewhere, but I just don't. In order to put in the form of a right Riemann Sum:Evaluate the following limit as a definite integral (Hint: Consider \(f(x) = x^4\))

\(\displaystyle \lim_{n \to \infty} \sum\limits_{k=1}^{n} \frac{k^4}{n^5}\)

\(\displaystyle \sum\limits_{k=1}^{n} f(x_i) \Delta x\) where \(\displaystyle \Delta x = \frac{b - a}{n}\)

Wouldn't I need to know a value for \(a\) and \(b\)? It doesn't seem like those were given anywhere... or am I supposed to intuit it from the problem somehow? And how can I deal with the \(n^5\) term?

I feel like I'm missing something obvious, and I'll probably be ashamed once you guys point it out to me, but for now I'm completely at a loss. Any help would be greatly appreciated.