Groundwater contamination with the gasoline additive methyl tert-butyl ether (MBTE) is a significant problem. Data was collected from 223 wells recording the pH, Dissolved oxygen, the percentage of land adjacent to industrial sites, the well class (public or private), the aquifer type (bedrock or unconsolidated), well depth, distance from the well to a fuel source, and the MTBE level. This data is included in the file Problem3.mtw. a) Fit and report a complete second order model to the data, recoding the categorical data with dummy variables b) Perform an appropriate hypothesis test to test the significance of the second order terms. c) After removing any insignificant quadratic terms, perform an appropriate test to test the significance of the interaction terms. d) After removing any insignificant interaction terms, if possible test the significance of the linear terms in the model. e) Report the final model after removing all the insignificant terms (if possible). Discuss the residual plots, and comment