Question

A statistician believes that in her town each child born has a 50% chance of being a girl, independently of all other children. There are 281 three-child families in her town; 39 of these families have no girls, 94 have one girl, 115 have two girls, and the remaining 33 have three girls.

1) If the statistician’s belief is correct, the probability that a three-child family in the town will have exactly one girl is ______%.

2) If the statistician’s belief is correct, then among the three-child families in the town what is the expected number of families that have exactly one girl?

3) If the statistician’s belief is correct, then among the three-child families in the town what is the expected number of families that have no girls?

Answer 1

4) The P-value of the appropriate test is about ________%.