PRO Engineering is considering whether to purchase or lease a piece of earthmoving equipment. The data associated with the purchase are as follows Initial cost = $150,000 Residual value = $12,000 Maintenance cost = $1,800/per year Operator cost per day = $300/day If the equipment is rented, the operator cost is incurred, at the rate of $300 per day and $100 for the daily rental of the equipment. Determine the minimum number of days per year the equipment must be used to justify the purchase. Use an interest rate of 7%