8-11 Explain what a dummy variable is and how it is used in regression analysis. 8-12 How do we know when high correlation exists? Is high correlation the same as cause and effect? 8-13 What does the...

8-11 Explain what a dummy variable is and how it is used in regression analysis.

8-12 How do we know when high correlation exists? Is high correlation the same as cause and effect?

8-13 What does the coefficient of determination (R-squared) measure?