Ononot — A sequence an is defined by a1 = 2 and a{n+1} = an \cdot r.

Guest Session: 1 Question Remaining. Create Account to save progress.

Geometric Sequenceshard

0:00.0

A sequence $a_n$ is defined by $a_1 = 2$ and $a_{n+1} = a_n \cdot r$ . If $\sum_{n=1}^{4} a_n = 45$ and $r=2$ , what is the value of $a_4$ ?