Question: what are the chances of having a fourth girl?
Answer: Couples with 4 children: 12.5% of couples have 4 girls or 4 boys, 37.5% will have 1/3 and 50% will have 2/2. Couples with 5 children: 6.25% have 5 the same sex and in couples with 6 children, 3.125% will have the same sex.