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37 votes
Find the rate if a principal of $8,500 earned $3,230 interest in 4 year

User RedDragonWebDesign
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1 Answer

19 votes
19 votes

Answer: The rate was 11.5%.

I = $3,772, P = $8,200, r = ?, t = 4 years

We will use the simple interest formula to find the rate.

Write the formula. I = Prt

Substitute the given information. 3,772 = 8,200r(4)

Multiply. 3,772 = 32,800r

Divide.

3,77232,800=32,800r32,800(6.4.4)

Simplify. 0.115 = r

Write as a percent. 11.5% = r

Check your answer. Is 11.5% a reasonable rate if $3,772 was earned in 4 years?

3,772=?8,200(0.115)(4)(6.4.5)

3,772=3,772✓(6.4.6)

Write a complete sentence that answers the question. The rate was 11.5%.

User Katrin Leinweber
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