Solved

How do I use Excel to calculate a trend (x, y coordinates)?

Posted on 2014-01-12
2
240 Views
Last Modified: 2014-01-12
How do I use Excel to calculate the missing value in the data table below indicated by question marks?

Date:               4/1/2005                                  9/15/2009                                          7/31/2013
Amount:             $22,918.80                                   $13,000.00                                              ???????
Comments:      Purchased New       Appraised by Otts Farm Equipment                        Excel
0
Comment
Question by:bobbat
  • 2
2 Comments
 
LVL 23

Expert Comment

by:Danny Child
ID: 39775459
This should do it... I'll explain below.
EE---linear-trend.xlsx
0
 
LVL 23

Accepted Solution

by:
Danny Child earned 500 total points
ID: 39775470
As I understand it, the items concerned have lost a fixed price per day since their purchase, and you want to extend this trend to the new date.

So, for the loss per day, it's just
(PurchasePrice - 1stAppraisalPrice) / (1stAppraisalDate - PurchaseDate)

And therefore the loss at the 2nd date is
LossPerDay * (2ndAppraisalDate - PurchaseDate)

and the overall remaining value is
PurchasePrice - LossToDate

The attached table does all this in one hit, and the benefit of making it a table is that it makes the (admittedly complex) formula a bit more readable.

I added the 2nd row as a simple test of the maths.
If an item loses 200 in 10 days, it should lose 600 in 30 days... which it does.
note, with the dates, to get a 10 day gap, you have to specify the 1st and the 11th of the month, not the 10th...

Hope this is what you're after!
cheers, Danny
0

Featured Post

Free Tool: Subnet Calculator

The subnet calculator helps you design networks by taking an IP address and network mask and returning information such as network, broadcast address, and host range.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Drop Down List with Unique/Distinct Values (Part II - ComboBox or ListBox and Data Validation List Bonus!) David Miller (dlmille) Intro This article focuses on delivering unique, sorted lists to list objects (e.g., ComboBox, ListBox) and Dat…
Improved? Move/Copy Add-in Replacement - How to avoid the annoying, “A formula or sheet you want to move or copy contains the name XXX, which already exists on the destination worksheet.” David Miller (dlmille)  It was one of those days… I wa…
This Micro Tutorial demonstrates how to create Excel charts: column, area, line, bar, and scatter charts. Formatting tips are provided as well.
This Micro Tutorial will demonstrate how to use longer labels with horizontal bar charts instead of the vertical column chart.

828 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question