The sales director for an industrial supplies firm has collected information describing the performance and personal characteristics of 80 members of her sales force. The data in file XR17066 include the percent of sales quota the salesperson achieved last year, age, number of years with the firm, and personal appearance (very neat, about average, or a little sloppy). In the data file, a very neat person is coded as neat = 1, average = 0, a person of average neatness is coded as neat = 0, average = 1, and a sloppy person is coded as neat = 0, average = 0. With y = percent of sales quota, perform a linear regression using the other variables as predictors.