4. Families in a Faraway LandIn a faraway land,
• 20% of families have no children,
• 20% of families have exactly 1 child,
• 30% of families have exactly 2 children,
• 20% of families have exactly 3 children,
• 10% of families have exactly 4 children,
• no families have more than 4 children, and• 55% of children are
boys.
(a) If you randomly choose a family from this faraway land, what
is the expected number of children...