China's Population. To convince yourself that a one-son policy would lead to an average of two children per family, with
equal numbers of boys and girls, do the following. Suppose
that 10,000 families are having children according to the one-
son policy. Describe the general makeup of all the families
(that is, start with the fact that 5000 families have a boy as
their first and therefore only child, and continue on). Use
this process to show that the average number of children is
two and that boys and girls are equal in number.