Which approach seemed to give values closer to your actual height? the formula using only gender or the formula using both ethnicity and gender? why do you think this is the case?

It is in all likelihood the formula that utilized both ethnicity and gender that gave values nearer to your genuine height. The reason is that distinctive ethnicities have a tendency to have certain highlights in like manner, and one of those highlights is a novel connection between bone length and tallness. Since the formulas that incorporate ethnicity and gender will probably coordinate all the more intimately with the qualities that are particular to your race, these recipes will probably work.