The finance manager has provided you with the following overhead cost function in a Ym(X)+b format: Total monthly overhead costs $2.53 (machine hours used) +$4,350. Given this cost function, identify the (a) variable cost; (b) the cost driver; (c) the fixed costs; and (d) whether these monthly overhead costs are considered variable, fixed, or mixed in total. (Round variable cost to 2 decimal places, e.g. 15.25.) (a) Variable cost $ per machine hour used (b) Cost driver is (c) Fixed costs $ (d) These monthly overhead costs are considered in total