A “study” asked people to identify their favorite game and then calculated the mortality rate (deaths per 1,000 people that year) for each game category [28]. For example, of those people whose favorite game is bingo, 41.3 of 1,000 people died that year. The mortality rates were 27.2 for bridge, 0.05 for poker, and 0.04 for the video game Mortal Kombat. The study concluded that The numbers reveal an alarming truth: bingo may not be as safe as some people have assumed. “This is the first evidence we have seen that violent video games actually reduce the death rate,” says PlayGear CEO Pete Elor, “It comes as a blow to the head for people who advocate less violent forms of entertainment.” Lawyer Gerald Hill thinks the church and community need to take action: “When you look at the numbers, there’s just no way you can get around it. Bingo is claiming lives right and left….” We can only hope that this study will cause people to think twice before engaging in such risky behavior.

a. Explain why there might be sampling bias in this study.

b. Suppose that all four of these games are completely safe in that playing the game has no effect at all on one’s health. Explain how it could still be the case that the mortality rate is much higher for bingo players than for Mortal Kombat players.

c. What would have to be done to have a controlled experiment?