The controller of Sunland Production has collected the following monthly cost data for analyzing the behavior of electricity costs. Determine the fixed costs and unit variable costs using the high-low method. Total fixed costs $ Variable cost per machine hour $ What electricity cost does the cost equation estimate for a level of activity of 460 machine hours? Electricity cost $ By what amount does this differ from March's observed cost for 460 machine hours? Amount differ What electricity cost does the cost equation estimate for a level of activity of 790 machine hours? Electricity cost $ By what amount does this differ from June's observed cost for 790 machine hours? Amount differ $