TREND function estimates future values of a given data set using the ``least squares'' line that best fit to your data. @known_y's is the y-values where y=mx+b and @known_x's contains the corresponding x-values. @new_x's contains the x-values for which you want to estimate the y-values.
If @known_x's is omitted, an array {1, 2, 3, ...} is used. If @new_x's is omitted, it is assumed to be the same as @known_x's. If @known_y's and @known_x's have unequal number of data points, TREND returns #NUM! error.