In Problem 19 of Chapter 5, data from the 1990 Census were shown for 26 randomly selected Metropolitan Statistical Areas (MSAs). Of interest are factors potentially associated with the rate of owner occupancy of housing units. Three variables included in the data set were as follows:
OWNEROCC: Proportion of housing units that are owner-occupied (as opposed to renter occupied)
OWNCOST: Median selected monthly ownership costs, in $
URBAN: Proportion of population living in urban areas
Use the output given next to answer the following questions:
a. Fit a model with OWNEROCC as the response and OWNCOST and URBAN as the predictors. State the estimated model.
b. Perform variables-added-last tests for each predictor.
c. Does there appear to be any problem with collinearity? Explain.
d. Examine each plot of studentized residuals versus the predictor. Are any violations of the assumptions of linear regression evident from the plot?
e. Determine residuals and leverage values. Do any observations seem bothersome? Explain.