Trendline Percent
 

I created a chart with a trendline. How can I figure out the percent of
increase from the formula generated from trendline?

y = 2.1973x + 3211.2
R² = 0.0046

Thanks!

Answer: Trendline Percent
 

1. Identify the starting and ending points of the trendline. For example, if your trendline is based on monthly sales data, you might use the first and last months of the data set.
2. Plug the x-values (i.e., the time periods) for the starting and ending points into the equation for the trendline. For example, if the starting point is January and the ending point is December, you would plug in 1 for x in the equation for January and 12 for x in the equation for December.
3. Calculate the y-values (i.e., the sales figures) for the starting and ending points using the trendline equation. For example, if the equation for January is y = 2.1973(1) + 3211.2, the sales figure for January would be 3213.4 (rounded to the nearest tenth).
4. Calculate the percent increase between the starting and ending points using the following formula:
   
   Percent increase = ((Ending value - Starting value) / Starting value) x 100
   
   For example, if the sales figure for January was 3213.4 and the sales figure for December was 3300.0, the percent increase would be:
   
   ((3300.0 - 3213.4) / 3213.4) x 100 = 2.7%
   

So in this case, the trendline suggests that there was a 2.7% increase in sales over the course of the year. Keep in mind that this calculation assumes that the trendline accurately represents the underlying data and that there are no other factors influencing the sales figures.

Trendline Percent
 

With an R² value that low, I would not trust any derived data.
best wishes
--
Bernard V Liengme
Microsoft Excel MVP
http://people.stfx.ca/bliengme
remove caps from email

"rml" wrote in message
...
I created a chart with a trendline. How can I figure out the percent of
increase from the formula generated from trendline?

y = 2.1973x + 3211.2
R² = 0.0046

Thanks!

Trendline Percent
 

It should be a small increase of say 2% or so. Anyways, how would I convert
those equations to a percent?

Thanks.

"Bernard Liengme" wrote:

With an R² value that low, I would not trust any derived data.
best wishes
--
Bernard V Liengme
Microsoft Excel MVP
http://people.stfx.ca/bliengme
remove caps from email

"rml" wrote in message
...
I created a chart with a trendline. How can I figure out the percent of
increase from the formula generated from trendline?

y = 2.1973x + 3211.2
R² = 0.0046

Thanks!

Trendline Percent
 

The percentage increase in Y depends on your X values.
=2.1973*(X_new-X_old)/(2.1973*X_old + 3211.2) and format as percentage.
--
David Biddulph

rml wrote:
It should be a small increase of say 2% or so. Anyways, how would I
convert those equations to a percent?

Thanks.

"Bernard Liengme" wrote:

With an R² value that low, I would not trust any derived data.
best wishes
--
Bernard V Liengme
Microsoft Excel MVP
http://people.stfx.ca/bliengme
remove caps from email

"rml" wrote in message
...
I created a chart with a trendline. How can I figure out the
percent of increase from the formula generated from trendline?

y = 2.1973x + 3211.2
R² = 0.0046

Thanks!

Trendline Percent
 

Hi,

Since this is a linear equation, the delta Y/delta X is the same regardless
of the x position. Here is the basic idea

=(Y2-Y1)/(X2-X1)

Since you can use any values I chose 1 and 2 as my X positions and
substituted in you other numbers:

=((2.1973*2+3211.1)-(2.1973*1+3211.1))/(2-1)

the answer is 2.1973

However, as Bernard said an R squared value of 0.0046 basically means the
trend line Excel found does not match the data at all. Most likely this is
because the data is not linear, so you should test the other types of
trendlines.

--
If this helps, please click the Yes button.

Cheers,
Shane Devenshire


"David Biddulph" wrote:

The percentage increase in Y depends on your X values.
=2.1973*(X_new-X_old)/(2.1973*X_old + 3211.2) and format as percentage.
--
David Biddulph

rml wrote:
It should be a small increase of say 2% or so. Anyways, how would I
convert those equations to a percent?

Thanks.

"Bernard Liengme" wrote:

With an R² value that low, I would not trust any derived data.
best wishes
--
Bernard V Liengme
Microsoft Excel MVP
http://people.stfx.ca/bliengme
remove caps from email

"rml" wrote in message
...
I created a chart with a trendline. How can I figure out the
percent of increase from the formula generated from trendline?

y = 2.1973x + 3211.2
R² = 0.0046

Thanks!

Trendline Percent
 

When the OP asked for "percent of increase", I assumed that he was asking
not for the slope =(Y2-Y1)/(X2-X1) but for the increase as a percentage of
the original value =(Y2-Y1)/Y1. In each case, of course, the answer would
need to be expressed as a percentage. My interpretation may be supported by
the fact that the OP said he was expecting about 2%, whereas Shane's formula
gives 219.73%.
--
David Biddulph

Shane Devenshire wrote:
Hi,

Since this is a linear equation, the delta Y/delta X is the same
regardless of the x position. Here is the basic idea

=(Y2-Y1)/(X2-X1)

Since you can use any values I chose 1 and 2 as my X positions and
substituted in you other numbers:

=((2.1973*2+3211.1)-(2.1973*1+3211.1))/(2-1)

the answer is 2.1973

However, as Bernard said an R squared value of 0.0046 basically means
the trend line Excel found does not match the data at all. Most
likely this is because the data is not linear, so you should test the
other types of trendlines.


The percentage increase in Y depends on your X values.
=2.1973*(X_new-X_old)/(2.1973*X_old + 3211.2) and format as
percentage. --
David Biddulph

rml wrote:
It should be a small increase of say 2% or so. Anyways, how would I
convert those equations to a percent?

Thanks.

"Bernard Liengme" wrote:

With an R² value that low, I would not trust any derived data.
best wishes
--
Bernard V Liengme
Microsoft Excel MVP
http://people.stfx.ca/bliengme
remove caps from email

"rml" wrote in message
...
I created a chart with a trendline. How can I figure out the
percent of increase from the formula generated from trendline?

y = 2.1973x + 3211.2
R² = 0.0046

Thanks!