Читать книгу Probability and Statistical Inference - Robert Bartoszynski - Страница 97

Clearly, the number of ways a group can be divided into two equal parts is . The number of ways boys can be divided evenly is and the same holds for girls. Thus,

(3.30)

which, based on (3.29), can be approximated by

For example, in the case of 16 boys and 16 girls , the approximate chances of dividing both sexes evenly are about The exact value is 0.2756.