Question

determine whether the problem should be solved using the formula for an arithmetic sequence, arithmetic series, geometric sequence, or geometric series. Explain your answer in complete sentences. You do not need to solve.

Jackie deposited $5 into a checking account in February. For each month following, the deposit
amount was doubled. How much money was deposited in the checking account in the month of
August?

Answer 1

"For each month following, the deposit amount was doubled." Which is more likely?

(1) the previous month's deposit has two added to it.
(2) the previous month's deposit is multiplied by 2.

Answer 2

would I use the geometric sequence formula?

Answer 3

As a matter of fact, yes! How'd you decide that?

Answer 4

because my first term is 5 and the common ratio is 2 and the n is the number im looking for.

Answer 5

Beautiful. Can you now write a tentative formula that will predict the nth term of a geometric sequence if your first term (a) is 5 and your common ratio, r, is 2?

Answer 6

i think it may be geometric series.
My reasons are as follows:
1) your adding up the sum at the end of the month
2) the sequence has a common ratio of 2

Answer 7

I know the geometric sequence formula is a(n)=a(1)r^(n-1)

Answer 8

You might write something such as \(a _{n}=\]) = some function of a and r

Answer 9

wait sorry, it''s a geometric sequence...lol

Answer 10

Cool. You have both a and r, so would you now please substitute those valules into the formula you've shared?

Answer 11

\[a _{n}=( ? )( ? )^{n-1}\]

Answer 12

You have this problem practically completed / solved. Substitute the values of a and r into the above formula.

Test this formula by letting n = 1. Is the first term 5, as expected?

If so, please now substitute n=6 (why??)

Next time, would you please let me know before you log off. OpenStudy tells me you're offline right now.