A rather common application of the IRR method is in so-called installment financing types of problems.These problems are associated with financing arrangements for purchasing merchandise “on time.” The total interest, or finance, charge is often paid by the borrower on the basis of what amount is owed at the beginning of the loan instead of on the unpaid loan balance, as illustrated in Figure 5-8. Usually, the average unpaid loan balance is about one-half of the initial amount borrowed. Clearly, a finance charge based solely on the entire amount of money borrowed involves payment of interest on money not actually borrowed for the full term. This practice leads to an actual interest rate that often greatly exceeds the stated interestrate.Todeterminethetrueinterestratebeingchargedinsuchcases,the IRR method is frequently employed. Examples 5-14, 5-15, and 5-16 are representative installment-financing problems.