Anyone Here REALLY Good with MS Excel/Graphs/Trendlines?

[1369]

I've got a graphing question I can't figure out I need help with.

[travis2]

what do you need? I'm reasonably good with Excel...

[1369]

I generated some "scatter" graphs and then plotted a linear trendline to show progress being made.

Question is, is it possible to determine from the first plot of the trendline (Not the first point in the graph), to the end of the trendline, what the percentage of deviation of the trendline from beginning to end (i.e. over a period of 1 year the trend has decreased "X" percent)?

I've questioned folks in the office and no one can seem to come up with the answer.

Thanks in advance Travis.

[CosmicCowboyXXX]

I've questioned folks in the office and no one can seem to come up with the answer.

well in that case you don't have a problem...pull a number out of your ass that makes you look good...who the **** is gonna know?

[travis2]

It sounds to me as though you are just looking for the slope of the trendline...am I understanding you correctly?

[1369]

Pretty much.

What I'm curious to know, is can you determine the change from the beginning of the trendline to the end and express that as a percentage increase/decrease?

[travis2]

Percent difference is easy...

Delta % = (new - old)/old*100

[1369]

Fair enough Travis, but how do I pull the "old" and "new" from the trendline when I can find no "points" on the graph axis?

[travis2]

What information did the trendline analysis routine give you?

[1369]

Trendline Analysis?

Easy on the high point scrabble words professor. I'm just a low-life construction hand with a laptop. I'm about half-tempted to drive a spud wrench through this thing trying to figure this out.

I clicked on the "Load Add-Ins" for Data Analysis, but it didn't do anything. Lemme bounce it off the desk a few times to get attention...

[travis2]

Easy there...

OK, try this...exactly what command did you use to generate that trendline?

[1369]

Ok Travis, I see the "Data Analysis" function, but it's only applicable when I have the graph worksheet up (I have about 40 different graphs on one sheet) and not on a specific graph. When the dialogue box opens, there is a bucketload of stastical/fancy options that a vaguely remember from classes in college (I spent more time at Eskimo Joe's than in stats).

I generated the trendline by highlighting the graph (Actually just clicking in the body of the graph) and then clicking on Chart/Add Trendline/Linear and based it on the data series I plotted in the graph.

[travis2]

I think you want to use a spreadsheet function rather than the graph function...the graph function will probably get you what you want, but without me seeing it, I will have a hard time steering you through that one.

Try using the TREND function.

Your input will look like:

TREND(y-value-range, x-value-range,first-x-value, last-x-value)

It will return the y-values for the two x-values you specify. Then plug those values into the Delta % formula I gave you.

[1369]

I'll give a crack manana Travis.

Thanks for the hand.

[travis2]

hope it helps...

Look up TREND in the Help files...also, LINEST would work...

[ducks]

bill gates makes this way to hard does he not

[TastesLikeChicken]

Sounds like a bad fan belt