User`s guide

Appendix B: More About Calculations
III
Cash-Flow Calculations
When NPV = 0, the solution for i% is the periodic internal rate of return.
NFV = NPV x SPFV(i % : N) where N =
TOTAL =
COUNT =
i% = periodic interest rate.
j = the group number of the cash flow.
CF
j
= amount of the cash flow for group j.
n
j
= number of times the cash flow occurs for group j.
k = the group number of the last group of cash flows.
Nj = = total number of cash flows prior to group j.
n
l
1 lj<≤
∑
NPV CF
0
CF
j
j 1=
k
∑
+=
11
i%
100
--------+
⎝⎠
⎛⎞
n
j
–
–
i%
100
--------
--------------------------------------
⎝⎠
⎜⎟
⎜⎟
⎜⎟
⎛⎞
× 1
i%
100
--------+
⎝⎠
⎛⎞
n
j
–
×
n
j
j 1=
k
∑
n
j
CF
j
×()
j 0=
k
∑
n
j
j 0=
k
∑