Three professors at George Washington University did an experiment to determine if economists are more likely to return found money than other people. They dropped 64 stamped, addressed envelopes with $10 cash in different classrooms on the George Washington campus. Forty-four percent were returned overall. From the economics classes 56 percent of the envelopes were returned. From the business, psychology, and history classes 31 percent were returned.
Let R = money returned; E = economics classes; and O = other classes.
- Write a probability statement for the overall percentage of money returned.
- Write a probability statement for the percentage of money returned out of the economics classes.
- Write a probability statement for the percentage of money returned out of the other classes.
- Is money being returned independent of the class? Justify your answer numerically and explain it.
- Based upon this study, do you think that economists are more selfish than other people? Explain why or why not. Include numbers to justify your answer.
OpenStax Statistics, 3.3 Two Basic Rules of Probability, exercise 48