Find a(7) in the geometric series in which S(5) = -61 and the common ratio is -3.

Question

-729
-574
2,680
2,188

Jamison just started a new job as a firefighter earning an annual salary for 38,500.00. his contract states that he will receive a 3% salary increase every year after his first year on the job. Find Jamison's total earnings over the course of his first six years as a firefighter.

$204,401.73
$44,632.05
$249,033.78
$14,014,000.00

Answer 1

Just apply your definitions:
sum(n) = a(r^n - 1)/(r-1)
sum(5) = a((-3)^5 - 1)/(-3-1) = -61
a(-244/-4) = -61
61a = -61
a = -1

so term(5) = ar^4 = -1(-3)^4 = 81

#2:
you have a GP with a = 38500, and r = 1.03

you want sum(6), so apply the above formula

Answer 2

for #1, I get a; -729
for #2, I get: c; $249,033.78
Are these correct?

Answer 3

yes, both are correct

Answer 4

for finite geometric series quick check connexus the answers are as follows:
Q1 is D (363)
Q2 is A (158,943.053
Q3. B ( -18.703)
Q4 is A -729
and Q5 is 249,033.78
100%, I just took the quiz

Answer 5

moonchild is 100% right