Calculate the factors [F/A, 7%, 20] and [A/G, 7%, 20] used in Problem 5.6.
By (5.4),
F/A = \frac{e^m – 1}{e^r – 1} (5.4) \\\\ [F/A, 7\%, 20] = \frac{e^{(0.07)(20)} – 1}{e^{0.07} – 1} – \frac{4.055200 – 1}{1.072508 – 1} = 42.1359and, By (5.8),
A/G = \frac{1}{e^r – 1} – \frac{n}{e^m – 1} (5.8) \\\\ [A/g, 7\%, 20] = \frac{1}{e^{0.07} – 1} – \frac{20}{e^{(0.07)(20)} – 1} = \frac{1}{1.072508 – 1} – \frac{20}{4.055200 – 1} = 7.2454