$\backslash$table$[[$Category$,,\backslash$table$[[$al Pooled$],[$Cost$]],$Types of Costs,Cost Driver$],[$Unit$,$$$,408,000,\backslash$table$[[$Indirect labor wages, supplies, factory utilities, machine$],[$maintenance$]],$Machine hours$],[$Batch$,,230,400,\backslash$table$[[$Materials handling, inventory storage, labor for setups,$],[$packaging$,$ labeling and shipping, scheduling$]],$Number of production orders$],[$Product$,,117,600,$Research and development,Time spent by research departmen$],[$Facility$,,312,000,\backslash$table$[[$Rent$,$ general utilities, maintenance, facility depreciation,$],[$administrative salaries$]],$Square footage$]]$

Additional data for each of the product lines follow:

$\backslash$table$[[,$Commercial,Home,Miniature,$],[$Direct materials cost,$$25\mathrm{.}12$ per unit,$$15\mathrm{.}12$ per unit,$$12\mathrm{.}12$ per unit,$-],[$Direct labor cost,$$10\mathrm{.}60$ per hour,$$8\mathrm{.}60$ per hour,$$9\mathrm{.}60$ per hour,$-],[$Number of labor hours,$6,000,12,000,2,000,20,000],[$Number of machine hours,$10,000,45,000,25,000,80,000],[$Number of production orders,$200,2,000,3,000,],[$Research and development time,$10\%,20\%,14,000,74,000],[$Number of units,$15,000,45,000,30,000,100,000],[$Square footage,$20,000,50,000,,]]$

Required

a$.$ Determine the total cost and cost per unit for each product line, assuming that overhead costs are allocated to each product line using direct labor hours as a companywide allocation base. Also determine the combined cost of all three product lines.

b$.$ Determine the total cost and cost per unit for each product line, assun hat an $3C$ system is used to allocate overhead costs. Determine the combined cost of all three product lines.

Note$-$ For all requirements, round intermediate calculations for allocation rates to $2$ decimal places and all other calculations to