# math models

If \$3800 is invested in a savings account for which interest is compounded quarterly, and if the \$3800 turns into \$4300 in 2 years, what is the interest rate of the savings account?

1. 👍
2. 👎
3. 👁
1. let the quarterly rate be i

then 3800(1+i)^8 = 4300
(1+i)^8 = 1.1315789....
take (1/8)th root , (exponent of 1/8)

1+i = 1.01557..
i = .01557...

annual rate is 4i = .06229

the rate is 6.229% per annum, compounded quarterly.

1. 👍
2. 👎
2. 4300=3800(1+i/4)^4t where t is 2, solve for i.

43/38= (1+i/4)^8

take the log of each side

log43-log38=8(1+i/4)
solve for i.

1. 👍
2. 👎
👤
bobpursley
3. I don't get it

1. 👍
2. 👎
4. 107.80

1. 👍
2. 👎

## Similar Questions

1. ### math

Suppose you put \$2000 in a savings account at an APR of 8% compounded quarterly. Fill in the table below. (Calculate the interest and compound it each quarter rather than using the compound interest formula. Round your answers to

2. ### Math

Suppose you deposit \$2000 in an account with an annual interest rate of 7% compounded quarterly. Use the formula A=P(1+r/n)^n*t and round each answer to 2 decimal places, if necessary. a. Find an equation that gives the amount of

3. ### FINANCE

You deposit \$2,000 in an account that pays 8% interest compounded semiannually. After 4 years, the interest rate is increased to 8.28% compounded quarterly. What will be the value of the account after 4 more years? (Do not round

4. ### UOG

An initial investment of \$12,000 is invested for 2 years in an account that earns 4% interest compounded quarterly. Find the amount of mnoey in the account at the end of the period.

1. ### magh

suppose you put money into teo different bank accounts. In account #1 you deposit \$500 and you will be earning 6% interest compounded quarterly. in account #2 you deposit \$600 and you will be earning 5% interest compounded

2. ### math

You deposit ​\$2000 in an account that pays 7 ​% interest compounded semiannually. After 2 ​years, the interest rate is increased to 7.32 ​% compounded quarterly. What will be the value of the account after a total of 4

3. ### Math

A person deposited \$500 in a savings account that pays 5% annual interest that is compounded yearly. At the end of the 10 years, how much money will be in the savings account?

4. ### Algebra

Calvin deposits \$400 in a savings account that accrues 5% interest compounded monthly. After c years, Calvin has \$658.80. Makayla deposits \$300 in a different savings account that accrues 6% interest compounded quarterly. After m

1. ### math

Money is invested in a savings account at 3.4% simple interest. After 1 year, there is \$1695.76 in the account. How much was originally invested?

2. ### Math

Peter has money in two savings accounts. One rate is 9% and the other is 11%. If he has \$400 more in the 11% account and the total interest is \$117, how much is invested in each savings account?

3. ### Lat math question for some days. Can y'all help?

Huan deposited \$850 into a college savings account earning 4.8% interest compounded annually. He also deposited \$850 into a second account earning 4.8% simple interest. He made no additional deposits. After 10 years, which account

4. ### Math , check my answer ?

Lynne invested \$35,000 into an account earning 4% annual interest compounded quarterly. She makes no other deposits into the account and does not withdraw any money. What is the balance of Lynne's account in 5 years? \$37,153.21