Yumiko invests $5000 in a Treasury Bond at 8.5% interest compounded 6 times per year.

  1. Find the equation that represents the account balance at time LaTeX: \displaystyle t .
  2. When will the account double? e.g. when will it be $10000. Round your solution to the nearest tenth of a year.

  1. Using the compounded interest formula gives LaTeX: \displaystyle A = 5000 \cdot 1.01416666666667^{6 t} .
  2. It will take about 8.2 years.