Chances for Male/Female

Why is it a 50-50 chance that a baby will be a boy/girl rather than something else, like 55-45, etc.?

Actually, there exists a probably of either 0 or 1 that a given baby is a boy (or girl).  As one cannot assign an intermediary probability (between 0 and 1) to a single event.  You can, however, assign an intermediary probability to a series of events; for example, what is the probability that a baby will be born in a given population.  Then you would use a proportion, and if you wanted to test the level of significance do a hypothesis test and so on.

TLDR

>>24
Care to explain your reasoning with more than an overly emotional array of ad hominem attacks --perhaps something substantive?

In the world of statistics--and to those who do not understand fucking basic probability, >>16 and >>25 was in fact correct--one cannot interpret cold data without further analysis, as it can be misleading.  That ratio alludes to the outside factors, as if it is established (I am terrible with biology, so I will assume you're correct) that the cell-production probability for let's say male is .5 as observed in the population of births, there must be an external force--that is just "common sense."  Statistics is not "ruining" /sci/ the corrosion of logic is.