Use a graphing utility to find the sum of the geometric sequence. Round answer to two decimal places, if necessary.
-$$4 + 12 + 36 + 108 + 324 + \ldots + 4 \cdot 310$$
A) 354,292
B) 354,294
C) 354,329
D) 354,272

Question

Quizplus · Accepted Answer

The sequence is geometric with the first term $a = 4$ and common ratio $r = 3$. The last term is $4 \cdot 310$. The sum of a geometric sequence is given by $S_n = a \frac{r^n - 1}{r - 1}$. Using a graphing utility, the sum is approximately 354,292.

Use a Graphing Utility to Find the Sum of the Geometric