Engineering Economic Analysis

94 MORE INTERESTFORMULAS

IALTERNATESOLUTION.

100 100 100

t t t

0-1-2-3-4-5 -

100 100 100

t t t

0-1-2-3-4-5

1

F F

Looked at this way, we first solve forFl'

FI = 100(F/A,15%,3) = 100(3.472)= $347.20

NowFIcan be considered a present sumPin the diagram

3-4-5

F

and so

F=FI(F/ P,15%,2)

= 347.20(1.322)

~ $459.00

:

]he slightly different value from the preceding computation is due to rounding in the compound

interest tables.

This has been a two-step solution:

FI =100(F/A,15%,3)

F-:- FI(F/P, 15%,2)

I"

- - .. ---'- -- - ...- - - --. -- ...- -.. -- - -- I