I updated the question with better screen shots. All 4 problems are part of 1 question, regarding the information on top of the first screen shot.

Please show all work. Thank you

Nova Company's total overhead cost at various levels of activity are presented below Month Machine-Hours Total overhead Cost Apr 51,000 $181,390 May 41,000 $156,490 61,000 June $206,290 71,000 July $231,190 Assume that the total overhead cost above consists of utilities, supervisory salaries, and maintenance. The breakdown of these costs at the 41,000 machine-hour level of activity is Utilities (variable) 53,300 41,000 Supervisory salaries (fixed) 62,190 Maintenance (mixed) Total overhead cost 156,490 Nova Company's management wants to break down the maintenance cost into its variable and fixed cost elements