VSLOPE function
VSLOPE(variableX,variableY[,filter]) returns the slope of the regression line of the independent variable variableX and the dependent variable variableY. An optional filter can be specified.
The equation for VSLOPE b is:
$$ b = \frac{ \sum_{}^{}{(x-\bar{x})(y-\bar{y})}} {\sum_{}^{}{(x-\bar{x})^2}} $$
Note that in comparison with the corresponding Excel SLOPE function, the order of the X and Y arguments is reversed.
Note
This function calculates a statistic on a variable. Be careful when you use this function in cells of the columns that correspond to the variable, because this actually adds a value to the variable which can lead to unexpected and faulty results. You can exclude the cell to avoid this.