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Isabel needs $29,260 for a future project. she can invest $5000 now at an annual rate of 11%, compounded semiannually. assuming that no withdrawals are made, how long will it take for her to have enough money for her project?

User Dayerman
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1 Answer

6 votes

Final answer:

Isabel will need approximately 8.14 years to have enough money for her project.

Step-by-step explanation:

To determine how long it will take for Isabel to have enough money for her project, we can use the compound interest formula:



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



Where:



  • A is the future amount
  • P is the present amount (initial investment)
  • r is the annual interest rate in decimal form
  • n is the number of times interest is compounded per year
  • t is the number of years



In this case, Isabel needs $29,260, so A = $29,260. Her initial investment is $5000, so P = $5000. The annual interest rate is 11% or 0.11, compounded semiannually, so r = 0.11 and n = 2. We need to find t.



Substituting the values into the formula:



$29,260 = $5000(1 + 0.11/2)^(2t)



Divide both sides by $5000:



5.852 = (1 + 0.055)^2t



Take the natural logarithm of both sides to eliminate the exponent:



ln(5.852) = ln((1 + 0.055)^2t)



We can solve for t by dividing both sides by ln((1 + 0.055)^2) and multiplying by the reciprocal of 2:



t = ln(5.852) / (2 * ln(1.055))



Using a calculator, we find that t ≈ 8.14 years.

User KevinResoL
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