If you borrow L dollars at an annual interest rate of r, for a period of m years, then the size of the montly payment, M, is given by the annuity equation: L=M \times \frac{1-(1+r)^{-12 m}}{r} An author needs to borrow $225,000 to buy the new house that he wants, and he can only afford to pay $800 per month. Assuming a 30 year mortgage, use the section method to determine what interest rate he can afford to pay. (Hint: Start with the interval [0.001, 0.002]) Should the author perhaps find some rich relatives to help him out here?

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