Price Demand Curve

This looks like something that Goal Seek could help you with. Have a look here: https://support.office.com/en-gb/art...ad=GB&fromAR=1

How do you want it to work? You need to give us some specific outcomes so that we can construct a formula that will do what you want. What are the rules? What is the logic behind the calculations?

I have price and demand at the beginning and the end of the curve (A-B). What I want to calculate is the demand on any point between A and B given the price (through a drop down menu).
Thanks

Worked examples, please.

Happy to help, but mathematically challenged!!!

To be able to create a formula for you, we need to know the logic behind the curve you have plotted - what is the equation? If it were a straight line, of course it would be easy, even for me!

Thanks for your reply!
My need is to understand which is the best mathematical formula to distribute those values between A and B...
I hope is a common business problem...
Any hint?
Thanks

No, no hint - sorry. I think I've been clear about how I can help, but without knowing the maths behind it, I can't. Someone else may understand it better.

Please don't quote whole posts, especially when you are responding to the one immediately preceding your own - it's just clutter. It's OK to quote if you are responding to a post out of sequence, but limit quoted content to a few relevant lines that makes clear to whom and what you are responding. Thanks!

For normal conversational replies, try using the QUICK REPLY box below.

Hi,

I've assumed this is a logarithmic curve plotting the two extremes of Demand/Price as 45000;1 & 1;961 (the 961 taken from your chart)

Plot the points as an xy scatter chart and add the trendline and trendline equation. Then use the equation in your table.

See attached.

Originally Posted by AliGW

No, no hint - sorry. I think I've been clear about how I can help, but without knowing the maths behind it, I can't. Someone else may understand it better.

Thanks for your support!

Originally Posted by Richard Buttrey

See attached.

I set up an excel for you but I see the Attachments button blank... How do I upload excel files as you just did?
Meanwhile I upload you an example of what I am looking for (G3).
Excel 4.png
Thanks

Unfortunately the attachment icon doesn't work at the moment, so to attach an Excel file you have to do the following: just before posting, scroll down to Go Advanced and then scroll down to Manage Attachments. Now follow the instructions at the top of that screen.

	B	C	D	E	F	G	H
1		Ass1	Ass2
2	Demand	45,000	1,000		Price	1,400
3	Price	1	1,000		Demand	218	G3: =EXP($B$6 * G2 + $C$6)
4
5	m	b
6	-0.00381047	10.7182282					B6:C6: {=LINEST(LN(C2:D2), C3:D3)}
7
8
9	Price	Demand
10	1	45,000	45000				D10: =EXP($B$6 * B10 + $C$6)
11	500		6721
12	800		2143
13	1,000	1,000	1000
14	1,200		467
15	1,400		218
16	1,500		149

It's a regression to extract the parameters of the exponential trendline that appears in the chart:

demand = exp(m * price + b)

See attached.

Note however that with the constraint you've set of a demand/price of 1000;1000, this results in negative demand above a price of 1000.

You may need to change the D2 and/or the D3 values, noting the change in the equation and adjusting the constant in the column C formulae.

It's an array formula.

Select both cells, paste the formula in the formula bar sans curly braces, press and hold the Ctrl and Shift keys, then press Enter.

What makes you think you can fit any random set of made-up numbers with a smooth mathematical function?

Originally Posted by ChiccoLisoFolmichino

Looks like if I test shg formula adding other assumptions it isn't working.
What I expect is to have the curve at the exact input (assumptions) point where available.
Any hint of why?
Thanks

Would you explain exactly the purpose of this exercise and explain what you are trying to achieve and demonstrate.

Seems to me you have two choices.
1. Use some known price/demand points and then decide whether to use a 'least squares' method to plot a linear relationship curve, or some other exponential/logarithmic relationship in order to derive a formula that will allow you to predict price/demand points outside of the known points.

2. Derive a complex formula for your whole population of points, using a calculus of differences process, which gives you an arithmetically consistent formula which satisfies all your points.

From your statement above you may be looking for #2