A city council is debating a proposal to convert a vacant downtown lot into a multi-use skatepark. An urban planning consultant presents the following data table comparing the projected costs and benefits over a 5-year period. | Metric | Projected Value | Margin of Error | |-------------------------|-----------------|-----------------| | Initial Construction Cost | $250,000 | +/- $20,000 | | Annual Maintenance | $15,000 | +/- $3,000 | | Annual Vandalism Repair | $8,000 | +/- $5,000 | | Projected Annual Revenue| $5,000 | +/- $1,500 | | Increase in Local Sales | 2% per year | +/- 0.5% | To calculate the worst-case net financial outcome for the city over 5 years, which calculation should be performed?