Question

I will give a medal HELP ! Keiko invested $2875 in a savings account which earns 3.15% interest compounded semiannually. What will the account be worth in 7 years?
$8,003.59

$4,438.20

$3,578.11

$3,207.34

Answer 1

the appropriate formula is as follows:\[A=P(1+\frac{ r }{ n })^{nt}\]
where r is the interest rate (as a decimal fraction), P is the initial amount invested, n is the number of times annually that interest is paid, and t is the number of years. Can you take this formula and apply it to your math problem?

Answer 2

yes i just dont undertsand what semiannually would be @mathmale

Answer 3

"semiannual" means "twice per year." Thus, your n =2.

Find r/n and nt, using the data given.

Answer 4

for 3.15 would i divide by 100 and then divide by 2 or just do 3.15 / 2 ? @mathmale

Answer 5

Yes: convert 3.15% to a decimal fraction: divide 3.15% by 100%.

Next, find r/n: that would be 0.0315/2. nt would be what?

Answer 6

.0315/2 is .01572 and nt would be 14 because i do 2*7 right? @mathmale

Answer 7

i meant .01575

Answer 8

Yes, you're doing fine.

\[A=$2875(1+0.01575)^{14}\]

Answer 9

so the answer would be C 3,578.11

Answer 10

@mathmale

Answer 11

Does that match any of the four given possible answers? If so, what's your conclusion?

Answer 12

Nice work!!

Choose the appropriate correct answer from the four that you were given.

Answer 13

Thank you for all of your help i found where i messed up at first @mathmale would you mind helping me through another problem?

Answer 14

Please go ahead and post it in the "Ask a question" box.