Question 907782: Marsha and Jan both invested money March 1, 2007. Marsha invested $9,000 at Bank A where the interest was compounded quarterly. Jan invested $6,000 at Bank B where he interest was compounded continuously. On March 1, 2010, Marsha had a balance of $10,678.42 while Jan had a balance of $6,943.92. What was the interest rate at each bank?
(Round to the nearest tenth of a percent)
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! Marsha and Jan both invested money March 1, 2007.
Marsha invested $9,000 at Bank A where the interest was compounded quarterly. Jan invested $6,000 at Bank B where he interest was compounded continuously.
On March 1, 2010, Marsha had a balance of $10,678.42 while Jan had a balance of $6,943.92. What was the interest rate at each bank?
Marsha Info::
A(3) = 9000(1+(i/4))^(4*3) = 10,678.42
(1+(i/4))^(12) = 1.1865
(1+(i/4) = 1.0144
i/4 = 0.0144
interest = 0.0576
rate = 5.8%
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B(3) = 6000*e^(3i) = 6943.92
e^(3i) = 1.1573
3i = ln(1.1573)
i = 0.0487
rate = 4.9%
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Cheers,
Stan H.
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(Round to the nearest tenth of a percent)
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