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Joni put $200 in an interest-bearing account with an annual compound interest rate of 5%. Joni determined that after 3 years, she will have a total balance of $230. Her work is shown below. Step 1: P = 200, r = 5, t = 3 Step 2: I = 200 ∙ 0.05 ∙ 3 Step 3: I = 30 Step 4: 30 + 200 = 230 Is Joni correct? Explain. Joni is not correct, because $230 is just the interest she will earn; she will have $430 total. Joni is not correct; $230 will be her balance after 1 year. After 3 years, she will have $290. Joni is not correct because she used the simple interest rate formula, not the compound interest rate formula. She will have $231.53. Joni is correct. She correctly applied the I = P · r · t formula, and will have $230.

User Dolphiniac
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2 Answers

1 vote

Answer:

Joni is not correct because she used the simple interest rate formula, not the compound interest rate formula. She will have $231.53.

Explanation:

Just did it

User Bhullnatik
by
6.1k points
3 votes

Answer:

Joni is not correct because she used the simple interest rate formula, not the compound interest rate formula. She will have $231.53.

Explanation:

Joni put $200 in an interest-bearing account with an annual compound interest rate of 5%. Joni determined that after 3 years, she will have a total balance of $230.

Step 1: P = 200, r = 5, t = 3

Step 2: I = 200*0.05* 3

Step 3: I = 30

Step 4: 30 + 200 = 230

Joni is not correct because she used the simple interest rate formula, not the compound interest rate formula. She will have $231.53.

Above it is given, that annual compound interest rate of 5%

So, she should have calculated using the compound interest formula.


A=p(1+r/n)^(nt)

So, amount becomes :


A=200(1+0.05)^(3)


A=200(1.05)^(3) = $231.53.

User Ritch
by
5.1k points
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