71. Lawn service: Dave and his sons run a lawn service, which includes mowing, edging, trimming,
and aerating a lawn. His fixed cost includes
insurance, his salary, and monthly payments on
equipment, and amounts to $4000/mo. The variable
costs include gas, oil, hourly wages for his
employees, and miscellaneous expenses, which run
about $75 per lawn. The average charge for full-
service lawn care is $115 per visit. Do a break-
even analysis to (a) determine how many lawns
Dave must service each month to break even and
(b) the revenue required to break even.