Question

Okay, there is like 5 things to figure out in this one. @jim_thompson5910

Answer 1

Here's the assignment.

Answer 2

ok let me read it over

Answer 3

Alrighty :)

Answer 4

ok I think I know what to do, but I need to do a bit of research to confirm. One second.

Answer 5

I can wait :) You are great help.

Answer 6

ok have you learned about compound interest? or have you seen this formula before?

\[\Large A = P*\left(1+\frac{r}{n}\right)^{n*t}\]

Answer 7

Never seen this formula..

Answer 8

like i said this is on study island and there wernt lessons for it.

Answer 9

hmm strange how they ask you questions when they don't have lessons for it

Answer 10

anyways

P = amount deposited
r = interest rate
n = compounding frequency
t = time in years

Answer 11

how much money is put into the account?

Answer 12

$500

Answer 13

so P = 500

Answer 14

the interest rate is r = 1.8% = 0.018

Answer 15

n = 12 because we are compounding monthly (12 times a year)

Answer 16

t will depend on what month it is

eg:
if we're at month 0, then t = 0/12 = 0
if we're at month 1, then t = 1/12 = 0.83333....
etc etc

Answer 17

Okay

Answer 18

Let's calculate month 1

Answer 19

P = 500
r = 0.018
n = 12

For month 1, the time in years is
t = 1/12 = 0.0833333333333333



Let's plug those values in to get this:

\[\Large A = P*\left(1+\frac{r}{n}\right)^{n*t}\]

\[\Large A = 500*\left(1+\frac{0.018}{12}\right)^{12*0.0833333333333333}\]

\[\Large A = 500*\left(1+0.0015\right)^{12*0.0833333333333333}\]

\[\Large A = 500*\left(1.0015\right)^{1}\]

\[\Large A = 500*1.0015\]

\[\Large A = 500.75\]

Answer 20

Use a calculator for much of these steps. If you don't have one, then use this

http://web2.0calc.com/

Answer 21

@jim_thompson5910 i think it may be simpler than this. It's interest rate each month. So each month it increases by 1.8%, making it a much easier problem.

Just multiply the last month by 1.018.

Answer 22

But there is more than 1 thing to figure out first i have to figure out the amount in the account over 4 months. so @jim_thompson5910 how do we do that?

Answer 23

oh my bad

@agent0smith is right. The annual rate isn't 1.8%. That's the monthly rate

Answer 24

Read my reply above^^

Answer 25

so based on what @agent0smith said, we just multiply the last month amount (500) by 1.018 to get the next month

Current month balance = (Previous month balance)*(1.018)

Current month balance = (500)*(1.018)

Current month balance = 509

Answer 26

month 0 = $500
month 1 = $509
to get month 2, multiply the previous month's balance (month 1) by 1.018 to get what?

Answer 27

518.162

Answer 28

month 2 balance = (month 1 balance)*(1.018)

month 2 balance = (509)*(1.018)

month 2 balance = 518.162

month 2 balance = 518.16 ... round DOWN to the nearest penny

Answer 29

month 3 balance = (month 2 balance)*(1.018)

month 3 balance = (518.16)*(1.018)

month 3 balance = 527.48688

month 3 balance = 527.48... round DOWN to the nearest penny

Answer 30

?

Answer 31

where are you stuck? @sarah.ranee

Answer 32

So 527.48688 rounded to the nearest penny is 527.48?

Answer 33

keep in mind it says that `banks always round down to the nearest cent`

Answer 34

so even if you had 527.48999999999999999999999999999 it would round down to 527.48

the bank would NOT round to 527.49

Answer 35

the bank is trying to save as much money as possible. Even if it's a single cent

Answer 36

Okay. SO now month 4 is 536.97464 rounded Down to 536.97?

Answer 37

Is that right?

Answer 38

month 4 balance = (month 3 balance)*(1.018)

month 4 balance = (527.48)*(1.018)

month 4 balance = 536.97464

month 4 balance = 536.97 ... rounding down to the nearest cent

Answer 39

yes you are correct

Answer 40

Yeah! :) SO now we have to find out that, If she had graphed the function what the Y intercept would be. Im totally not good with the whole y intercept thing.

Answer 41

the y intercept occurs when the x value (aka the input) is 0

the input in this case is the number of months

at month 0, the y value is 500

so basically this is the starting amount

Answer 42

`If she had graphed the function ` then her graph would cross through 500 on the y axis

Answer 43

Okay.

Answer 44

the graph would slope upward and be some sort of curve to indicate that her money is growing over time

Answer 45

the steeper the curve, the faster the growth

Answer 46

So does this mean the Y intercept would be 500?

Answer 47

yes

Answer 48

months goes on the x axis

Answer 49

account balance goes on y axis