a$.$A cellular telephone bill when a flat fee is charged for the first $500$ minutes of useAnswer $1(1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)$per month and additional use costs $$0\mathrm{.}25$ per minuteb.Total selling and administrative costsAnswer $2(1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)$c$.$Total labor costs when employees are paid per unit producedAnswer $3(1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)$d$.$Total overtime premium paid production employeesAnswer $4(1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)$e$.$Average total cost per unitAnswer $5(1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)$f$.$Salaries of supervisors when each one can supervise a maximum of $10$ employeesAnswer $6(1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)$g$.$Total idle time costs when employee are paid for a minimum $40-$hour weekAnswer $7(1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)$h$.$Materials costs per unitAnswer $8(1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)$i$.$Total sales commissions.Answer $9(1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)$j$.$Electric power consumption in a restaurantAnswer $10(1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)$k$.$Total costs when high volumes of production require the use of overtimeAnswer $11(1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)$and obsolete equipmentl.A good linear approximation of actual costsAnswer $12(1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)$m$.$A linear cost estimation valid only within the relevant range