To convert an annual interest rate to the quarterly rate, you can simply divide by four. For example, an annual percentage rate of 8 percent would equate to a quarterly rate of 2 percent.
How to Convert Annual Interest Rate to Quarterly Interest - PocketSense
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Account #3: Quarterly Compounding The annual interest rate is restated to be the quarterly rate of i = 2% (8% per year divided by 4 three-month periods). The present value of $10,000 will grow to a future value of $10,824 (rounded) at the end of one year when the 8% annual interest rate is compounded quarterly.
Mathematics of Future Value - AccountingCoach
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Fraction of one year
1/365 (ignoring leap years, which have 366 days)
www.math.hawaii.edu > ~ramsey > CompoundInterest