Yumiko invests $10700 in a Certificate of Deposit at 8.3% interest compounded 2 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 $21400. Round your solution to the nearest tenth of a year.

  1. Using the compounded interest formula gives LaTeX: \displaystyle A = 10700 \cdot 1.0415^{2 t} .
  2. It will take about 8.5 years.