Consider the genetic cross for sex in humans xx is female and xy is male a family has four children all girls

there would be a 50% chance of having a boy and a 50% chance of having a girl

Because the earth is not round ,but it may seem round when viewed from ,our planet but true some points earth is not round was an oblate spheroid -a square that it squashed as globe however is not even a perfect oblate spheroid.in fact isaac newton's first proposed that earth was not perfectly round but it was an oblate spheroid instead.that mean a square that is squashed as its poles and swollen at the