SOLUTION: A promissory note will pay $59,000 at maturity 21 years from now. If you pay $20,000 for the note now, what rate compounded continuously would you earn?

Algebra ->  Finance -> SOLUTION: A promissory note will pay $59,000 at maturity 21 years from now. If you pay $20,000 for the note now, what rate compounded continuously would you earn?      Log On


   



Question 1143333: A promissory note will pay $59,000 at maturity 21 years from now. If you pay $20,000 for the note now, what rate compounded continuously would you earn?
Answer by Theo(13342) About Me  (Show Source):
You can put this solution on YOUR website!
continuous compounding formula is f = p * e ^ (r * t)

f = future value = 59,000
p = present value = 20,000
n = 21

you want to solve for r.

formula becomes 59,000 = 20,000 * e ^ (r * 21)

divide both sides of he formula by 20,000 to get 2.95 = e ^ (r * 21)

take the natural log of both sides of the equation to get ln(2.95) = ln(e ^ (r * 21))

since ln(e ^ (r * 21) = r * 21 * ln(e) and since ln(e) = 1, the formula becomes:

ln(2.95) = r * 21

solve for r to get r = ln(2.95) / 21 = 0.051514532

confirm by replacing r in the original equation to get:

59,000 = 20,000 * e ^ 0.051514532 * 21)

this results in 50,000 = 50,000, confirming the solution is correct.