



 
Hi Dan. The formula for compound interest is: A(t) = P(1+r/m)^{tm} where A(t) is the amount you have after t years, P is the principal, r is the annual interest rate and m is the number of times per year it is compounded. You want r. You asked about "per month" compounding, so 150 days is about 5 months. 94300 = 80000(1 + r/12)^{5} 94300/80000 = (1+r/12)^{5} So your interest rate is about 40.13 % annualized. Stephen La Rocque>  


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