ClassicSound is a specialty company that hand-crafts violins. They current produce 10 violins a month with 5 employees, but wish to ramp up to 20 violins a month. Logically, if it takes 5 workers to provide 10 per month, they would need to hire 5 more to produce 20. This is an example of which approach to forecasting? Group of answer choices proportional addition incremental expansion staffing ratios patterned hiring