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Set 10: Exponential Functions

Explanation

Answer: A

$10,000 is invested at 5% annual interest compounded monthly for 3 years. What is the approximate final value?

Use: A=P(1+rn)ntA = P(1 + \frac{r}{n})^{nt}

A.

$11,614.72

✓ Correct
B.

$11,500.00

C.

$11,576.25

D.

$12,000.00

Detailed Explanation

Choice A is correct. Choice A is the correct answer. Apply monthly compounding. 1. Values: P=10000P = 10000, r=0.05r = 0.05, n=12n = 12 (monthly), t=3t = 3. 2. Calculate: A=10000(1+0.0512)12×3=10000(1.004167)36A = 10000(1 + \frac{0.05}{12})^{12 \times 3} = 10000(1.004167)^{36}. 3. Result: (1.004167)361.161472(1.004167)^{36} \approx 1.161472, so A11,614.72A \approx 11,614.72. Strategic Tip: Monthly compounding: divide rate by 12, multiply exponent by 12. Choice B is incorrect because this assumes simple interest. Choice C is incorrect because this uses quarterly compounding. Choice D is incorrect because the calculation is wrong.

Key Steps:

The correct answer is $11,614.72

Why others are wrong:
B: Choice B is incorrect and may result from a calculation error.
C: Choice C is incorrect and may result from a calculation error.
D: Choice D is incorrect and may result from a calculation error.

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