Yumiko invests $10400 in a Savings Account at 9.2% 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 $20800. Round your solution to the nearest tenth of a year.

  1. Using the compounded interest formula gives LaTeX: \displaystyle A = 10400 \cdot 1.046^{2 t} .
  2. It will take about 7.7 years.