4. Calculate the variable cost per blade of laser cutting with this new system. Assume that the variable cost of the laser is $4/hour, that the laser cuts at the rate of 40 inches per minute, that a typical blade of 14 inches diameter sells for $25, and the same computer and software will be used as currently. Material load time for a 10-blade sheet of steel is one minute. Use a 3-inch arbor hole size and assume that a cut tooth doubles the cut distance. Compare this cost to the cost of variable overhead per blade in Exhibit 1. 5. Using the data in question 4, estimate the costs and rev- enues for this new system to perform a payback analysis (in months). What do you have to assume in addition to do the payback analysis