Sorry to bother with such a simple question, but what is the problem with this?
=IF(OR([Average 6mths]7 * 1.5 > [Current Monthly Usage]7, [ Average 6mths]7 * 0.5 < [Current Monthly Usage]7), 1, 0)
I am just trying to return 1 if between 50 and 150% and 0 of outside that range