E A nutritionist wants to understand the influence of income and healthy food on the incidence of smoking. He collects 2009 data on the percentage of smokers in each state in the U.S. and the corresponding median income and the percentage of the population that regularly eats fruits and vegetables. A portion of the data is shown in the accompanying table; the complete data set can be found on the text website, labeled Smoking.
a. Estimate: Smoke = β + β1 Fruits/Vegetables + β2Median Income + ε.
b. At the 5% level of significance, are the explanatory variables individually and jointly significant? Explain.
c. Use the sample correlation coefficients to evaluate the potential problem of multicollinearity.