??????? (a) Let \( \left(a_{n}ight) \) be a sequence of real numbers and \( a \in \mathbb{R} \). Suppose \( a_{n} ightarrow a \). Show that \[ \frac{a_{1}+a_{2}+\cdots+a_{n}}{n} ightarrow a \] (b) Find 1 answer