Problem: Find out the following limit
\[
\lim_{n \to \infty} \frac{1 + \sqrt{2} + \sqrt[3]{3} + \dots + \sqrt[n]{n}}{n}.
\]
Solution: We know that if $\displaystyle \lim_{n \to \infty} a_n = a$, then
\[
\lim_{n \to \infty} \frac{a_1 + a_2 + \dots + a_n}{n} = \lim_{n \to \infty} a_n.
\]
Therefore,
\[
\lim_{n \to \infty} \frac{1 + \sqrt{2} + \sqrt[3]{3} + \dots + \sqrt[n]{n}}{n} = \lim_{n \to \infty} \sqrt[n]{n}.
\]
Let us find the limit of $\sqrt[n]{n}$ as $n$ approaches to infinity. For $n \gt 1$, since $\sqrt[n]{n} \gt 1$,
\[
\sqrt[n]{n} = 1 + h_n,
\]
where $h_n$ is a positive sequence of real numbers. Thus,
\begin{align*}
& n = \left( 1 + h_n \right) ^n \geq \frac{n(n-1)}{2}h_n^2 \\
\implies & n \geq \frac{n(n-1)}{2}h_n^2 \geq 0 \\
\implies & \frac{2}{n-1} \geq h_n^2 \geq 0.
\end{align*}
So by Sandwich's theorem, we conclude that $h_n^2 \rightarrow 0$ and hence $h_n \rightarrow 0$. Therefore,
\[
\lim_{n \to \infty} \sqrt[n]{n} = 1.
\]
Hence,
\[
\lim_{n \to \infty} \frac{1 + \sqrt{2} + \sqrt[3]{3} + \dots + \sqrt[n]{n}}{n} = 1.
\]