Archer Company is a wholesaler of custom-built air-conditioning units for commercial buildings. It gathered the following monthly data relating to units shipped and total shipping expense: Month Unit Shipped Total Unit shipped
January 3 $1800
February 6 $2300
March 4 $1700
April 5 $2000
May 7 $2300
June 8 $2700
July 2 $1200

Required:
a. 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?
b. 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.
c. 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 S217.86 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?
d. What factors, other than the number of units shipped, are likely to affect the company's shipping expense? Explain.