the fictional taj mahal indian grocery store had sales of us$50,000 in august and us$62,000 in september. there are 10 full-time workers in the store, each of whom worked 40 hours a week. in august, the store also employed four part-time workers, each of whom worked 15 hours a week. in september, eight part-time workers were employed, each for 10 hours a week. assuming there are four weeks in each month, and sales dollars are the output measure, what was the change in productivity from august to september?\