Pane of Glass Inc. produces custom glasswork for high-end homes and buildings. The following cost data relate to the company's labour costs. Units Produced Labour Cost July 400 $15,000 August 300 13,000 September 320 13,200 October 350 13,800 November 420 16,000 December 410 14,800 I Required: a) Using the high-low method, estimate the cost formula (write it in y=mx+b format). 1. Using your answer from part a.) above, assuming in the following month the company expects to make 250 units, what will be the company's estimated labour cost. b) Using the scattergraph method, estimate the cost formula. c) Using the least squares regression method, estimate the cost formula. d) Are there any factors other than the number of units produced that may contribute to a variation in labour cost