HP 12c Platinum - Sum-Of-The-Years-Digits Depreciation; Declining-Balance Depreciation; Modified Internal Rate of Return

190 Appendix : Formulas Used
Sum-of-the-Years-Digits Depreciation
SOYD
k
=
where W = integer part of k
F = fractional part of k.
(i.e., for k = 12.25 years, W = 12 and F = 0.25).
Keyboard function:
DPN
j
=
Program for partial year:
DPN
1
=
DPN
j
= for j ≠ 1
where LADJ =
Declining-Balance Depreciation
Keyboard function:
DPN
j
= for j = 1, 2, …, L
Program for partial first year:
DPN
1
=
DPN
j
= for j ≠ 1
Modified Internal Rate of Return
n = number of compounding periods.
NFV
P
= Net future value of the positive cash flows.
NPV
N
= Net present value of the negative cash flows.
W 1+
(
) W 2F+(
)
2
--
---------------------------------------
-
Lj–1+()
SOYD
L
------------------------- SBV SAL–()⋅
L
SOYD
----------------




Y
1
12
------


SBV SAL–(
)
⋅⋅
LADJ j–2+
SOYD
LADJ
--------------------------------




SBV D
1
– SAL–(
)
⋅
L
Y
1
12
------


–
R
BV
j 1–
FAC
T
100L
--------------
-
⋅
S
BV
FACT
100L
---------------
Y
1
1
2
----
--
⋅⋅
R
BV
j 1–
FAC
T
100L
--------------
-
⋅