Fits an exponential curve to a data set, and returns points on that curve.
GROWTH(yvalues, xvalues, new_xvalues, allow_factor)
data is a range or array containing numerical data.
yvalues and xvalues are single row or column ranges specifying points in a set of data.
GROWTH fits an exponential curve of the form y=bmx through these data points, using the linear regression method.
If allow_factor is FALSE the factor b in this equation is set to 1; if allow_factor is non-zero, TRUE or omitted the factor b is calculated from the data.
GROWTH returns an array of the y values of the exponential curve found, corresponding to the x values in new_xvalues (or if omitted xvalues). It must be entered as an array formula.
yvalues and xvalues must be the same size. new_xvalues may have a different size.
GROWTH(B2:B6, A2:A6, A2:A7)
when entered as an array formula in cell C2, where the x values in A2:A7 are 4, 5, 6, 7, 8, 9 and the y values in B2:B6 are 1.80, 3.20, 6.20, 12.30, 24.50, finds a best fit exponential curve for those points, and in C2:C7 returns y values on that curve for the x values in A2:A7.This example shows how GROWTH may be used to predict future values (A7,C7).