$1-15$ An assemble$-$to$-$order hardware company has two types of central processing units $($CPUs$),$ C$1$ and C$2,$ and two types of display monitors, M$1$ and M$2.$ Unit C$2$ is slightly more complex then C $1,$ as is M $2$ compared to M$1.$ The annual production volume and direct costs are shown in Table $1-9.$ Overhead costs for this past year are shown in Table $1-10.$ Assume that setup and testing costs are similar for both types of CPUs and monitors.

Table $1-9$

Table $1-10$

a$.$ Calculate the cost per unit of each product using the unit$-$based costing method by allocating overhead based on direct$-$labor costs.

b$.$ Calculate the cost per unit of each product using the activity$-$based costing method.

c$.$ Discuss the unit costs calculated using these two methods.