Chapter 14.1, Problem 29E

Mortgage The following tables show that a monthly mortgage payment, R, is a function of the amount financed, A, in thousands of dollars; the duration of the loan, n, in years; and the annual interest rate, r, as a percent. If $R=f\left(A,n,r\right)$, use the tables to find the following and then write a sentence of explanation for each.

$\left(\text{a}\right)f\left(90,20,8\right) \left(\text{b}\right)f\left(160,15,9\right)$

8% Annual Percent Rate

Monthly Payments (Principal and Interest)

Amount	10	15	20	25	30
Financed	Years	Years	Years	Years	Years
$50,000	$606.64	$477.83	$418.22	$385.91	$366.88
60,000	727.97	573.39	501.86	463.09	440.26
70,000	849.29	668.96	585.51	540.27	513.64
80,000	970.62	764.52	669.15	617.45	587.01
90,000	1091.95	860.09	752.80	694.63	660.39
100,000	1213.28	955.65	836.44	771.82	733.76
120,000	1455.94	1146.78	1003.72	926.18	880.52
140,000	1698.58	1337.92	1171.02	1080.54	1027.28
160,000	1941.24	1529.04	133830	1234.90	1174.02
180,000	2183.90	1720.18	1505.60	1389.26	1320.78
200,000	2426.56	1911.30	1672.88	1543.64	1467.52
9% Annual Percent Rate
Monthly Payments (Principal and Interest)
Amount	10	15	20	25	30
Financed	Years	Years	Years	Years	Years
$50,000	$633.38	$507.13	$449.86	$419.60	$40231
60,000	760.05	608.56	539.84	503.52	482.77
70,000	886.73	709.99	629.81	587.44	563.24
80,000	1013.41	811.41	719.78	671.36	643.70
90,000	1140.08	912.84	809.75	755.28	724.16
100,000	1266.76	1014.27	899.73	839.20	804.62
120,000	1520.10	1217.12	1079.68	1007.04	965.54
140,000	1773.46	1419.96	1259.62	1174.88	1126.48
160,000	2026.82	1622.82	1439.56	1342.72	1287.40
180,000	2280.16	1825.68	1619.50	1510.56	144832
200,000	2533.52	2028.54	1799.46	1678.40	1609.24

Source: The Mortgage Money Guide. Federal Trade Commission