Forecasting

[november678x]

Hello to all,

Does anyone know how I can forecast the 4th quarter amount for the data
below? I tried using the linear trend on my chart and selected 3 future
periods under the trend line options. This showed me a future trend but
it did not display what the totals will be. Any help would be
appreciated.

Thank you


Q1 - 2500

Q2 - 2350

Q3 - 2475

Q4 - ?

 

[David Biddulph]

"november678x" <[email protected]>
wrote in message

Hello to all,

Does anyone know how I can forecast the 4th quarter amount for the data
below? I tried using the linear trend on my chart and selected 3 future
periods under the trend line options. This showed me a future trend but
it did not display what the totals will be. Any help would be
appreciated.

Thank you


Q1 - 2500

Q2 - 2350

Q3 - 2475

Q4 - ?

Use the LINEST() function, which will calculate the parameters of your
y=mx+c linear fit. Having calculated the parameters, you can then evaluate
the value of y for any x. In your case, for Q4, y comes to 2416.667. [You
can of course plot this, to show it agrees with the trend line that Excel
plotted for you.]

 

[november678x]

Thank you for the reply. I am looking at the trend line formula on the
chart and it says:

Y=-12.5x+2466.7
R2 = 0.0242

To clarify this equation, If i say that the points move down every
12.5, the next value on the line will be 2466.7, and the closer R2 is
to 1.0 the more accurate the trendline, am I correct?

 

[David Biddulph]

"november678x" <[email protected]>
wrote in message

Thank you for the reply. I am looking at the trend line formula on the
chart and it says:

Y=-12.5x+2466.7
R2 = 0.0242

To clarify this equation, If i say that the points move down every
12.5, the next value on the line will be 2466.7, and the closer R2 is
to 1.0 the more accurate the trendline, am I correct?

2466.7 is the y value for x=0, i.e. the point where the line crosses the y
axis.

For more detail see
http://office.microsoft.com/en-us/assistance/HP052091551033.aspx