Engineering Economic Analysis

u + __ n

Uniform Series Compound Interest Formulas 95

One could substitute the value of FI frO!ll the first equation into the second equation and solve

forF,without computing Fl,

,
~;;.~ ;;; = =t-~ ;!iI:Ci

F=100(FlA, 15%,3)(P I P,15%,2)

=100(3.472)(1.322)

=$459.00

Consider the following situation:

30

t t t

0~1-2-3-4

1

i=15%

p

The diagram is not in a standardform, indicating that there will be a multiple-stepsolution. There

are at least three different ways of computing the answer. (It is important that you understand how

the three computations are made, so please study all three solutions.)

,:- --"-- j

SOLUfflON 1.

P=PI+ P2+ P3

=20(PI F,15%,2) +30(P I F,15%,3) +20(P I F,15%,4)

::; ~ ~:;:; :: ~

= 20(0.7561) + 30(0.6575) + 20(0.5718)

• $46.28

30

W t w

P= 0-1-1-3'--4 +0 ,--1-2'--3'--4 + 0-1-2-3-1

!;! ~

• -- - ---- -- ----- - - - -..------