Quantify trend line

[Brisbane Rob]

Hi

On a chart where the trend line completes the last couple of months
over a given period, is it possible to give a value to the points where
the trend line meets the future months? i.e. if the chart contains data
from say January thru August and a trend line tuns up to December, is
it possible to read values (other than visually) off the trend line?

Any ideas welcome.

Thanks

 

[random1970]

Rob,

Here's a thought.

Go in to where you added the trendline. Set it to "show equation on
chart". Set the equation up as a formula in your spreadsheet and input
the necessary information (i.e. the x value). It will give you an exact
value based on the equation used to generate the trendline.

 

[Guest]

On a chart where the trend line completes the last couple
of months over a given period, is it possible to give a value
to the points where the trend line meets the future months?

By point to the trend line on the chart itself? None that I know
of.

i.e. if the chart contains data from say January thru August
and a trend line tuns up to December, is it possible to read
values (other than visually) off the trend line?
Any ideas welcome.

Consider the following. Highlight two adjacent columns in a
spreadsheet, enter the formula =linest(yRange [,xRange]),
then press ctrl-shift-Enter to enter the array formula. You
probably want to omit the xRange argument.

The result in the first column is the x-multiple "m" (slope),
and the second column is the offset "b" (y-intercept) such
that the (y) "value" of the trend line is y = m*x + b.

Thus, if you have data for Jan through Aug such that the
corresponding x intercepts are 1-8, the Dec estimate would
be the result of:

=m*12 + b

 

[Brisbane Rob]

Thanks for the ideas - I'll give them a go today.