A retail store had sales of $45,000 in April and $56,000 in May. The store employs eight full- 8. 6.67% increase time workers who work a 40-hour week. In April the store also had seven part-time workersat 10 hours per week, and in May the store had nine part-timers at 15 hours per week (assumefour weeks in each month). Using sales dollars as the measure of output, what is the percentage change in productivity from April to May?