I'm confused on how to start answering this question. I'm aware that I need to use the variable cost/unit formula but on how to figure the correct numbers.

Question 1 4 Marks Selected data about Pitkin Company's manufacturing operations at two levels of activity are given below: Number of units produced 10,000 15,000 Total manufacturing costs $157,000 $225,000 Direct material cost per unit Direct labour cost per unit $6 Required: Using the high-low method, estimate the cost formula for manufacturing overhead. Assume that both direct material and direct labour are variable costs