Answer
$28,697,812$
Work Step by Step
We have to compute the sum of the geometric sequence:
$\sum_{n=1}^{15} 4\cdot 3^{n-1}$
The elements of the geometric sequence are:
$a_1=4$
$r=3$
$n=15$
Use a graphing utility to find the sum of the geometric sequence:
$sum\left(seq\left(4\cdot 3^{n-1},n,1,15\right)\right)=28,697,812$
