Question

Jose invests $3, 250 at 6% interest compounded annually. What will be the balance in the account after 3.5 years?

Answer 1

@campbell_st

Answer 2

ohhhhh thank you!

Answer 3

well its simply a case of

\[A = 3250(1 + 0.06)^{3.5}\]

where A is the future value of the investment

Answer 4

Ok I will calculate it.

Answer 5

ugg I got 12057.5

Answer 6

What did I do wrong? @campbell_st

Answer 7

okay, what do you get for 1+0.06?

then what do you get for that quantity to the 3.5 power?

Answer 8

Yeah! Whpalmer4!

Answer 9

1.06

Answer 10

good, that's what I expected :-)

Answer 11

I even tried 3250 (1.06)^3.5

Answer 12

well, \[3250*(1.06)^{3.5}\]IS what you want to calculate

Answer 13

why don't you try just calculating \(1.06^{3.5}\)

Answer 14

I did this on my calculator : 1.06 *3.05 = X then X * 3250

Answer 15

ok I will calculate what you typed. Just sec

Answer 16

No, you have to raise 1.06 to the 3.5 power.

Answer 17

3.71 so far

Answer 18

it's the same as multiplying \(1.06*1.06*1.06*\sqrt{1.06}\)

Answer 19

What are you using for a calculator?

Answer 20

You're just multiplying, not doing exponentiation

Answer 21

basic calculator. I got 3.18 now

Answer 22

Okay, that won't work. You need something that has exponentiation. You can use google:

https://www.google.com/#q=1.06%5E3.5&safe=off

Answer 23

you type in 1.06, then press the \(y^x\) button, then 3.5

Answer 24

I don't have that on mine :(

Answer 25

use google, like I suggested.

Answer 26

lol I was just now.

Answer 27

sorry, it's labeled \(x^y\) on the google keypad. just to the left of the 0

Answer 28

1.22

Answer 29

Yes! Multiply that by 3250 and you'll have the correct answer

Answer 30

thanks for not giving up on me!

Answer 31

$3965

Answer 32

oh, I almost never do :-) it's frustrating how few students know how to use their calculators correctly, and unfortunately, the people most likely not to use their calculators correctly are also the ones most likely to not recognize that the answer they got doesn't make any sense. That's a bad combination :-)

Answer 33

You should do it with a few more decimal places. Don't clear the result and type in 1.22 again, do the 1.06^3.5 and then just multiply by 3250

Answer 34

correct answer is about $20 higher, and I'm sure Jose wants the extra $20 :-)

Answer 35

My answer choices are
$3932.50
$3985.23
$4752.00
$5200.00

Answer 36

I see that google will let you just enter 3250*1.06(x^y)3.5 = and get the right result. back in my day, calculators didn't understand the proper order of execution, so you wouldn't necessarily get the right ansewr

Answer 37

ok so just add it to the amount?

Answer 38

no, do as I instructed. press AC to clear everything out, then enter \[3250\text{x}1.06x^y3.5=\]

Answer 39

k

Answer 40

$3985.23

Answer 41

: /

Answer 42

@whpalmer4

Answer 43

isn't that one of your answer choices, down to the last penny?

Answer 44

it is correct. you can check it by hand and eliminate 2 of the answers.

after 1 year, 6% interest added to 3250 = 3250 + 0.06*3250 = 3445
after 2 years, another 6% interest added to 3445 = 3445 + 0.06*3445 = 3651.70
after 3 years, another 6% interest added to 3651.70 = 3651.70 + 0.06*3651.70 = 3870.80

now half a year's interest added to 3870.80 is going to be 3870.80 + 1/2*6%*3870.80 = 3986.92, which is very close to your result, certainly closer than any of the other answer choices