Page 190 - Probability Demystified

CHAPTER 10 Simulation 179

Perform the experiment 10 times to represent the genders of the children of 10
1
families. (Note: The probability of a male or a female birth is not exactly ;
2
however, it is close enough for this situation.) The results are shown next.

Trial Outcome Number of boys

1 TTHT 1

2 TTTT 0
3 HHTT 2

4 THTT 1

5 TTHT 1

6 HHHH 4

7 HTHH 3

8 THHH 3

9 THHT 2

10 THTT 1

Results:
No. of boys 0 1 2 3 4

No. of families 1 4 2 2 1

In this case, there was one family with no boys and one family with four
boys. Four families had one boy and three girls, and two families had two
boys. The average is 1.8 boys per family of four.
More complicated problems can be simulated as shown next.

EXAMPLE: Suppose a prize is given under a bottle cap of a soda; however,
only one in five bottle caps has the prize. Find the average number of bottles
that would have to be purchased to win the prize. Use 20 trials.