In this activity you will investigate the relationship between age and a measure of flexibility. Flexibility will be measured by asking a person to bend at the waist as far as possible, extending his or her arms toward the floor. Using a yardstick, measure the distance from the floor to the fingertip closest to the floor.

1. Age and the measure of flexibility just described will be measured for a group of individuals. Our goal is to determine whether there is a relationship between age and this measure of flexibility. What are two reasons why it would not be a good idea to use just the students in your class as the subjects for your study?

2. Working as a class, decide on a reasonable way to collect data on the two variables of interest.

3. After your class has collected appropriate data, use them to construct a scatterplot. Comment on the interesting features of the plot. Does it look like there is a relationship between age and flexibility?

4. If there appears to be a relationship between age and flexibility, fit a model that is appropriate for describing the relationship.

5. In the context of this activity, write a brief description of the danger of extrapolation.