Choose the best cost driver for each pool: Salaries of production labor supervisors: direct labor hours machine hours setup hours number of setups number of units number of new product designs Salaries of machine technicians (they repair the machines; on average, machines break down every 500 hours): direct labor hours machine hours setup hours number of setups number of units number of new product designs direct labor hours machine hours setup hours number of setups number of units number of new product designs Design department costs (they develop new products): direct labor hours machine hours setup hours number of setups number of units number of new product designs Call center costs (they provide technical assistance to customers; on average, 5% of all units sold require some technical assistance): direct labor hours machine hours setup hours number of setups number of units number of new product designs