Rensing Groomers is in the dog-grooming business. Its operating costs are described by the following formulas: Grooming supplies (variable) Direct labor (variable) y=$0+$4xy=$0+$13xy=$9,600+$1x Overhead (mixed) Milo, the owner, has determined that direct labor is the cost driver for all three categories of costs. (a) RENSING GROOMERS Flexible Budget ActivityLevel Direct Labor Hours 550 600 680 Variable Costs Grooming Supplics $ 5 $ Direct Labor Overhead Total Variable Costs Overhead Total Variable Costs Fixed Costs Overhead Total Fixed Costs Total Costs