17.65  The production engineer for the manufacturing plant in Exercise 17.61 has just included another vari- able: the worker's gender, coded as 1 5 female and 0 5 male. File XR17065 contains the expanded set of data. With y 5 productivity (units/hour), x1 5 number of units in the backlog area, and x2 5 gender, fit a first- order model with no interaction term. Interpret the par- tial regression coefficients and the R2 value. At the 0.02 level, is the model significant?

17.66  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 5 1, average 5 0, a person of average neatness is coded as neat 5  0, average 5 1, and a sloppy person is coded as neat 5 0, average 5 0. With y 5 percent of sales quota, perform a linear regression using the other variables as predic- tors. Interpret the partial regression coefficients and the R2 value for the model. At the 0.05 level, is the model significant?