After trying a variety of different formulas for returning the last numeric value in a column, I settled on the following two.
Both of these formulas work very well and are still able to return the last numeric value even if the range contains blanks, error values (like #N/A), and text values.
The value 9.99999999999999E+307 is the largest number you can enter in a cell. The range doesn't have to be a full column. You could use B5:B100 instead of A:A.