Exercises


1. Change the slope and watch how the scatterplot changes. How does the slope affect Pearson's r, the variance explained, the variance unexplained, and the standard error of the estimate?

2. How would the correlation between height and weight be affected if you only considered people over 6' tall?

3. If Y were perfectly predictable by X, what would the standard error of the estimate be?

4. For what value of slope does the size of the standard error of the estimate not affect r?

5. For a given standard deviation of X, what affect on the variance explained does doubling the slope have?