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.
• The equation for FORECAST is a+bx, where:

  

  and:

  

Example

FORECAST(30,{6,7,9,15,21},{20,28,31,38,40}) equals 10.60725