EXAMPLE 8 We want a boy

Belief in this phony “law of averages” can lead to consequences close to disastrous. A few years ago, “Dear Abby” published in her advice column a letter from a distraught mother of eight girls. It seems that she and her husband had planned to limit their family to four children. When all four were girls, they tried again—and again, and again. After seven straight girls, even her doctor had assured her that “the law of averages was in our favor 100 to 1.” Unfortunately for this couple, having children is like tossing coins. Eight girls in a row is highly unlikely, but once seven girls have been born, it is not at all unlikely that the next child will be a girl—and it was.