So... I'm working on the reproduction of alien species, and I've run into a bit of a problem that is beyond my current math skills.
Males produce 5 types of "sperm". The "soma" contains 25% of the genetic information required, 4 types of "seed" each contain 6.25%. One of each is needed to combine with an egg to create an embryo.
A combination of "seeds" determines the sex of the embryo. Given 4 factors, each of which can be either M or F (or M/F/Neutral, if that makes it easier) , I need a combination matrix which results in 4 times as many males as females. 
 Don't worry: They're matriarchal—both biologically and culturally. :)