2. Meanwhile, Serena Williams, Controller, has gathered data on overhead costs and direct labor-hours over the past 12 months. List and discuss the different approaches Serena can use to estimate a cost function for overhead costs using direct labor-hours as the cost driver. 2. Meanwhile, Serena Williams, Controller, has gathered data on overhead costs and direct labor-hours over the past 12 months. List and discuss the different approaches Serena can use to estimate a cost function for overhead costs using direct labor-hours as the cost driver