What is the approximate probability that a human offspring will be female?

P(female offspring) = 0.5 = 1/2

Reason,

In the human genetic system, a male has 'XY' chromosomes

A female has 'XX' chromsomes. I will designate the femle chromosomes as X' & X" to distinguish .

Hence Male is XY

Female is X'X"

They can match in the following manner.

XX' = female

XX" = female

YX' = male

YX" male.

So you can see that there are two female outcomes and two male outcomes, out of a total of four(4) possible outcomes.

So 2/4 = 1/2 = 0.5 in both cases.

Hence P( female outcome) = 0.5

NB In reality, with a deeper understaning of statisitical and genetic analysis, slightly more females are born that males. Also males are slightly weaker at birth, there by making males less likely to survive at birth. This difference is only about M:F :: 49% : 51% , so equality of numbers remains roughly equal.