HP 17bII manual Yield of a Discounted or Premium Mortgage, Additional Examples

For instructions on entering Solver equations, see “Solving Your Own Equations,” on page 29.

If you know the dates for the course of the loan, rather than the number of days, use this for an actual-calendar basis:



or use this for a 360-day basis:



DATE1 = the date the loan commences.

DATE2 = the date the loan ends.

Yield of a Discounted (or Premium) Mortgage

The annual yield of a mortgage bought at a discount or premium can be calculated given the original mortgage amount (PV), interest rate (I%YR), periodic payment (PMT), balloon payment amount (if any) (FV), and the price paid for the mortgage (new PV).

Remember the cash-flow sign convention: money paid out is negative, money received is positive.

Example: Discounted Mortgage. An investor wishes to purchase a $100,000 mortgage taken out at 9% for 20 years. Since the mortgage was issued, 42 monthly payments have been made. The loan is to be paid in full (a balloon payment) at the end of its fifth year. What is the yield if the purchase price of the mortgage is $79,000?

1.Since the payment amount (PMT) is not given, calculate it first. To

do this, first assume 20 years’ amortization on the original mortgage with no balloon payment (so N = 20 ⋅ 12, FV = 0, PV =－100,000, and I%YR = 9).

2.Since the balloon amount is not given, calculate it (FV) next. Use PMT from step 1, but change N to 5 years (N = 5 ⋅ 12).

14: Additional Examples 191

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