Trend in single column

[Sunline]

Hi all , i have 2 and 1/2 years of data in col AA and want to apply trend function to it .
the numbers are only single or 2 digit .
Not actually sure if its the forecast or growth one i should be using .
Just wanting to see how accurate it would of been based at the begining of sheet .
many thanks . Kevin .

 

[RalphA]

Highlight the column with the dates, hold down the Ctrl key, and highlight the column with the data, column AA. Now, click on the Chart Wizard, select xy(Scatter), and get your chart done. Then, right-click on the resulting curve, select Add Trendline, and select the type that you believe is most suited. If the resulting trendline seems inadequate, just repeat the last step, and select a more appropriate treneline. If this is not what you need, please post again, with a better description.

 

[Sunline]

Thanks RalphA for reply , i have again asked wrong question , sorry .
eg , running down the col , there might be 22,3,10,4,6,8,2,1,11,9,7,17,20,5 etc covering now at 80,000 rows and climbing
Based on what has occured in history and realising that a certain amount of stats are needed before an assumption can be made by a formular or computer .
Is there a function that will extend to the 80,001 row or next 200 rows
thankyou , Kevin .

 

[RalphA]

With your data in column AA, select the beginning range you want to use to do your forcast, and copy to another column. Now, highlight your dates column, your data column AA, and your beginning range column, and do a scatter chart. Now, for the column AA series, select a trendline. Do the same for the beginning range series, chose forcast, and choose a different color. Now, you should be able to compare, not only the actual data vs forcasted trendline, but, also, the actual data trend vs the forcasted trendline. And, by copying different ranges for the beginning range, you should be able to get an even better range selection.
A WORD OF CAUTION: Please note that trend lines are simply mathematical "best fit" curves, which, very frequently, are totally inapplicable to many real-life situations. They do help us make up our minds (sometimes) as to what might be a better decision.