F IL E Healthy living has always been an im portant goal for any society. In a recent ad campaign for Walt Disney, First Lady M ichelle Obama shows parents and children tha t eating well and exercising can also be fun (USA Today, September 3 0 , 2010). Consider a regression model that conjectures tha t fruits and vegetables and regular exercising have a positive effect on health and smoking has a negative effect on health. The sample consists o f the percentage of these variables observed in various states in the U.S in 2009. A portion of the data is shown below;

the com plete data set can be found on the text website, labeled Healthy Living.

State Healthy

(%)

Fruits/Vegetables

(%)

Exercise

(%)

Smoke

(%)

AK 88.7 23.3 60.6 14.6 AL 78.3 20.3 41 16.4 WY 87.5 23.3 57.2 15.2 SOURCE: Centers for Disease Control and Prevention.

a. Estimate the model Healthy = β 0 + β1 Fruits/Vegetables +

β 2Exercise + β3 Smoke + ε.

b. Analyze the data to determine if m ulticollinearity and heteroskedasticity are present.