Some examples of highly correlated variables (X: independent, Y: dependent)are:

a) Temperature (X), ice cream sales (Y).

b) Temperature (X), cost of heating (Y).

c) Height of fathers (X), height of sons (Y).

d) Speed of cars (X), time to destination (Y)

Choose another example of naturally highly correlated variables. Your choice. "As a students study time increases, so does his/hers test average.

1. Just guess a possible correlation coefficient (you will use to answer questions below).

2. Is the association positive or negative?

3. What is the coefficient of non-determination.

4. What percent of the variance of Y is explained by X.

5. Is regression a good idea? Why?