Depreciation - different results on HP30b and on paper

[toml_12953]

(03-12-2021 12:05 AM)FabioBrasil Wrote:  Hello.
I come again to kindly ask for help from you who know a lot about HP. I cannot make the result of the calculation of decreasing depreciation (DecBal) provide the same result on the HP30b calculator and on paper.

The problem consists of the following:
- Cost (Czero)= $ 25000
- Salvage = $ 5000
- Life = 15 years
- Factor =10.174%

On paper D (n) = Czero * (1- Factor) ^ n
in year 1 I have 22,456.50
in year 3 I have 18,119.49
in year 6 I have 13,132.64
in year 12 I have 6,898.65
(n = year use as Factor 10.174%)

On the HP30b calculator (use as Factor 10.174%):
in year 1 I have 24,830.70 (R.Book)
in year 3 I have 24,494.94
in year 6 I have 24,000.08
in year 12 I have 23,040.16
Where am I going wrong? I couldn't get the answer on the Learning Modules.

Thanks!

It looks like your paper version is correct.

Code:


DECLARE FUNCTION D

INPUT PROMPT "Cost? ":Czero
INPUT PROMPT "Salvage? ":Salvage
INPUT PROMPT "Factor? ":Factor

LET n = 1

DO UNTIL D(n) <= Salvage
   PRINT n,USING$("$##,###.##",D(n))
   LET n = n + 1
LOOP

FUNCTION D(n)
   LET D=Czero*(1-Factor)^n
END FUNCTION

END

Cost? 25000
Salvage? 5000
Factor? .10174
 1                      $22,456.50
 2                      $20,171.78
 3                      $18,119.50
 4                      $16,276.02
 5                      $14,620.10
 6                      $13,132.65
 7                      $11,796.53
 8                      $10,596.35
 9                      $ 9,518.28
 10                     $ 8,549.89
 11                     $ 7,680.03
 12                     $ 6,898.66
 13                     $ 6,196.79
 14                     $ 5,566.33
 15                     $ 5,000.01