Given the geometric sequence:
$9, 3.75, 1.5625, \ldots$
Find an explicit formula for $a_n$.
$a_n =$
Find $a_{11}$ =
Find $S_{11}$ =
Find $S$ =
Note: Your answer to part one should be a function in terms of $n$. Your other answers should be decimals, accurate to at least 5 places.