Forcast function
Posted by Martin Stubbs on November 09, 2001 4:12 AM
Can anybody give me a good example of how this function works!
Posted by Lev Yashin on November 09, 2001 7:17 AM
From Excel Help (example at the end) :-
FORECAST
Calculates, or predicts, a future value by using existing values. The predicted value is a y-value for a given x-value. The known values are existing x-values and y-values, and the new value is predicted by using linear regression. You can use this function to predict future sales, inventory requirements, or consumer trends.
Syntax
FORECAST(x,known_y's,known_x's)
X is the data point for which you want to predict a value.
Known_y's is the dependent array or range of data.
Known_x's is the independent array or range of data.
Remarks
If x is nonnumeric, FORECAST returns the #VALUE! error value.
If known_y's and known_x's are empty or contain a different number of data points, FORECAST returns the #N/A error value.
If the variance of known_x's equals zero, then FORECAST returns the #DIV/0! error value.
Example
FORECAST(30,{6,7,9,15,21},{20,28,31,38,40}) equals 10.60725
