The analogous condition for the foreign exporter can be used to solve for foreign reaction curve p* = r*(p). Our savings rate, guaranteed to rise, did not even hold steady. Let's look at the code for an Average() function: Public Function Average(ByVal dblReturn1 As Double, _ ByVal dblReturn2 As Double ) As Double Return ( dblReturn1 + dblReturn2 )/2 End Function Now let's review the four elements of a function.