Dodge It Company's total monthly shipping costs fluctuate with the volume of units shipped. Data 6 from the last six months is as follows: Total Shipping Cost Month # of Units January 1,600 $3,200 February 1,685 3, 170 March 1,870 3,540 April 1,980 3,770 May 2, 100 3,900 June 1,880 3.540 Required: 1. Determine the variable cost per unit and the total monthly fixed cost using the high-low method. (5 marks) 2. State the cost formula for the shipping cost. (2 marks) 3. Is it appropriate to use the cost formula created in part 2 for an activity level of 2,050 units? Explain. (2 marks) 4. Describe the behaviour of a fixed cost when the level of activity increases. Provide one example of a fixed cost. (2 marks)