3 CLERICAL 6.8. Clerical staff work hours. In any production pro- cess in which one or more workers are engaged in a variety of tasks, the total time spent in production varies as a function of the size of the work pool and the level of output of the various activities. For example, in a large metropolitan department store, the number of hours worked (y) per day by the clerical staff may depend on the following variables: :61 = Number of pieces of mail processed (open, sort, etc.) x2 = Number of money orders and gift certi- cates sold 373 = Number of window payments (customer charge accounts) transacted X4 =Number of change order transactions pro- cessed X5 = Number of checks cashed X6 = Number of pieces of miscellaneous mail pro- cessed on an \"as available\" basis X7 = Number of bus tickets sold The output counts for these activities on each of 52 working days were recorded, and the data saved in the CLERICAL le. (a) Conduct a stepwise regression analysis of the data using an available statistical soft- ware package. (b) Interpret the }? estimates in the resulting stepwise model. (c) What are the dangers associated with drawing inferences from the stepwise model