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How long would it take a $5000 deposit to double, if invested at a 9.25% rate and

compounded daily?

A) Approximately 6.74 years
B) Approximately 7.49 years
C) Approximately 8.22 years
D) Approximately 9.10 years

1 Answer

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Final answer:

To determine the time to double a $5000 deposit at a rate of 9.25% compounded daily, we use the compound interest formula and solve for time (t), which is approximately 7.49 years, making option B) the correct answer.

Step-by-step explanation:

To determine how long it will take for a $5000 deposit to double in value with an interest rate of 9.25% compounded daily, we can use the formula for compound interest. The formula is A = P(1 + r/n)^(nt), where:

  • A is the amount of money accumulated after n years, including interest.
  • P is the principal amount (the initial sum of money).
  • r is the annual interest rate (decimal).
  • n is the number of times that interest is compounded per year.
  • t is the time in years.

To double the original deposit of $5000, we set A to $10000 and solve for t. The annual interest rate of 9.25% as a decimal is 0.0925, and since the interest is compounded daily, n is 365. Plugging the values into the formula gives us:

10000 = 5000(1 + 0.0925/365)^(365t)

To solve for t, we first divide both sides by 5000:

2 = (1 + 0.0925/365)^(365t)

Now, take the natural logarithm of both sides:

ln(2) = 365t * ln(1 + 0.0925/365)

And solve for t:

t = ln(2) / (365 * ln(1 + 0.0925/365))

Calculate the right side to find t:

t ≈ 7.49 years

Therefore, the correct answer is B) Approximately 7.49 years.

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