The following data relating to units shipped and total shipping expense have been assembled by Archer Company, a wholesaler of large, custom-built air-conditioning units for commercial buildings: Units Total Shipping Month Shipped Expense January 3 $1,800 February 6 $2,300 March 4 $1,700 April 5 $2,000 May 7 $2,300 June 8 $2,700 July 2 $1,200 Required: 1. Prepare a scattergraph using the data given above. Plot cost on the vertical axis and activity on the horizontal axis. Is there an approximately linear relationship between shipping expense and the number of units shipped? 2. Using the high-low method, estimate the cost formula for shipping expense. Draw a straight line through the high and low data points shown in the scattergraph that you prepared in requirement 1. Make sure your line intersects the Y axis. 3. Comment on the accuracy of your high-low estimates assuming a least-squares regression analysis estimated the total fixed costs to be $910.71 per month and the variable cost to be $217.86 per unit. How would the straight line that you drew in requirement 2 differ from a straight line that minimizes the sum of the squared errors