You and your friend are playing a coin toss game where if you toss heads you win $1, and if you toss tails you lose $1. You toss nine heads in a row and your friend is getting frustrated because they're running out of money. They think they are "due" to win the next toss because it would break the streak. Is this true? Explain to your friend why or why not this is the case.

Read the following scenario and explain why the doctors conducting the research could establish causality without doing an experiment. Doctors had long observed that most cancer patients were smokers. A series of observational studies comparing smokers and "similar" nonsmokers showed a strong association with smoking and death from lung cancer. The subjects were similar in the sense of characteristics such as age, gender, and overall health.