What is the most appropriate statistical procedure to use given the description of the data and the hypothesis.

a. A statistical consultant for a professional baseball team is preparing a report advising whether or not to offer a contract to a player. In that report, she makes predictions about the player's future performance from that player's past performance based on models (the models are based on observations of hundreds of different other players).

choices

1. regression

2. chi-squared test of statistical independence

3. one sample t test

b. An investment firm wants to assess how effective their product is. They take a sample of 20 of the people who invest with them and compare their earnings to the (known) national mean of investor earnings. Using the mean and standard error of their sample investor earnings, they wish to test the hypothesis that their investors make more than the national average.

choices

1. One-sample t-test

2.chi-squared test of statistical independence

3. binomial confidence interval

c. A social psychologist observes helping behavior in three different physical locations. His hypothesis is that the number of people who show helping behavior ("helpers") will differ by location. While his research assistant pretends to be in distress, he records how many people stop to help, and records the following data:

Location A	Location B	Location C
23 Helpers	77 Helpers	44 Helpers

1. One-sample t-test

2. regression

3. chi-squared test of statistical independence