GARY CORP HAS THE FOLLOWING DATA: VC/UNIT $57.60 VC % 60% FIXED COSTS $374,400 TAX RATE 40% HOW MANY UNITS MUST GARY SELL TO BREAK EVEN? 5. REFER TO QUESTION 4. ASSUME GARY HAD AFTER-TAX NET INCOME = $235,008. WHAT IS GARY'S MARGIN OF SAFETY IN UNITS?

I need help with #4. the answer is 17,250. I just need to know the process of how too get that answer.