LINEST


Returns a table of statistics for a straight line that best fits a data set.

Syntax:

LINEST(yvalues, xvalues, allow_const, stats)

yvalues is a single row or column range specifying the y coordinates in a set of data points.
xvalues is a corresponding single row or column range specifying the x coordinates. If xvalues is omitted it defaults to 1, 2, 3, ..., n. If there is more than one set of variables xvalues may be a range with corresponding multiple rows or columns.
LINEST finds a straight line  that best fits the data, using linear regression (the "least squares" method). With more than one set of variables the straight line is of the form .
if allow_const is FALSE the straight line found is forced to pass through the origin (the constant a is zero; ). If omitted, allow_const defaults to TRUE (the line is not forced through the origin).

 to  are the line gradients; a is the y-axis intercept.
 to  are the standard error values for the line gradients;  is the standard error value for the y-axis intercept.
 is the determination coefficient RSQ;  is the standard error value for the y estimate.
F is the F statistic (F-observed value); df is the number of degrees of freedom.
 is the regression sum of squares;  is the residual sum of squares.


linest1.png



Example:

linest2.png



In the example above, cells A2:B8 contain the x,y values for a set of points. LINEST(B2:B8,A2:A8,1,1) returns the statistics for the best fit line through those points.


linest3.png


In the example above, you measure the floor area and count the windows of a sample of houses in the area, and make a table with the corresponding sale value (cells A2:C8). To predict the value of other houses in the area you might use: value = a + b1*floor_area + b2*num_windows, where a, b1 and b2 are constants. LINEST(A2:A8,B2:C8,1,1) returns appropriate statistics for that equation.







 
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