On 01/10/2013 10:38 AM, Hylton Conacher (ZR1HPC) wrote:
Hi,
I am using Calc 3.4.5 on openSuSe Linux 11.2
I am working on a spreadsheet to cater for the monthly measurement of
household electricity consumption, new unit purchase and costing of
used units.
The electricity supplier gives me the first 150 units of electricity
at R1.29 per unit. The next 350 units are costed at R1.35 per unit.
Thereafter the units cost me R1.60 per unit. The monetary values per
set amount of unit changes when the electricity provider increases
prices i.e. the first 150 units might increase to R1.50 per purchased
unit, the next 350 units might be costed at R1.55 and thereafter units
will cost R2.00.
Each time I purchase electricity the units I am allocated are based on
the above sliding scale starting from 0.
How can I work out the number of units I will receive for a given
currency value i.e. R2000.00? i.e. x @ R1.29, y @ R1.35 and z @ R1.60=
R2000
In addition how could I work out the value of units consumed using the
above scale?
I am assuming the R values in the scale will change over time and
these can each be averaged to calculate the cost of units used, but
the problem is still to work out the formula.
Anybody have an idea if this is possible and where to start?
I am investigating results found on Google but would appreciate a
pointer or three.
Thanks
Hylton
If I understand your problem, you have a general equation of ax + by +
cz = d where a = 150, b = 350, c is currently unknown, d = 2000 (or any
value you choose), x = 1.29, y = 1.35, and c = 1.60. Solving for c, you
get c = (d - ax - by)/z.
Average cost per unit, ave, is ave = (a + b + c)/d., if I understand
your question The value c must be calculated prior to this step. In
terms of a Calc formula the c value would reference the cell with the
previous calculation.
In your spreadsheet I would set a table with named cells for each value
(a1 is Base_Rate and is 1.29, etc) so you can easily change the values
and see the values used.
--
Jay Lozier
[email protected]
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