We are given the following statistics about the number of children in the families of a small village.
There are 100 families: 10 families have no children, 40 families have 1 child each, 30 families have 2 children each, 10 families have 3 each, and 10 families have 4 each.
1. If you pick a family at random (each family in the village being equally likely to be picked), what is the expected number of children in that family?
- unanswered
2. If you pick a child at random (each child in the village being equally likely to be picked), what is the expected number of children in that child's family (including the picked child)?
- unanswered
3. Generalize your approach from part 2: Suppose that a fraction of the families have children each. Let be the number of children in a randomly selected family, and let and . Let be the number of children in a randomly chosen child's family. Express in terms of and using standard notation.
1 answer
1 answer