Project 5. Making decisions. Exercise 20.12 (page 476) reported the results of a study by the psychologist Amos Tversky on the effect of wording on people’s decisions about chance outcomes. His subjects were college students. Repeat Tversky’s study at your school. Prepare two typed cards. One says:

You are responsible for treating 600 people who have been exposed to a fatal virus. Treatment A has probability 1-in-2 of saving all 600 and probability 1-in-2 that all 600 will die. Treatment B is guaranteed to save exactly 400 of the 600 people. Which treatment will you give?

The second card says:

You are responsible for treating 600 people who have been exposed to a fatal virus. Treatment A has probability 1-in-2 of saving all 600 and probability 1-in-2 that all 600 will die. Treatment B will definitely lose exactly 200 of the lives. Which treatment will you give?

Show each card to at least 25 people (25 different people for each, chosen as randomly as you can conveniently manage and chosen from people who have not studied probability). Record the choices. Tversky claims that people shown the first card tend to choose B, while those shown the second card tend to choose A. Do your results agree with this claim? Write a brief summary of your findings: Do people use expected values in their decisions? Does the frame in which a decision is presented (the wording, for example) influence choices?