Please explain the cost variance in the highlighted task and show the math. Thank you

Niagara Construction $0.00 Prorated 87,172.90 $86,292.90 $880.00 27,050.00 60,122.90 Project Scope $0.00 Prorated $5,275.00 $5,275.00 $0.00 $5,275.00 $0.00 Create Scope $0.00 Prorated $0.00 $0.00 $0.00 $0.00 $0.00 New Homebuyer Review Scope $0.00 Prorated $2,075.00 $2,075.00 $0.00 $2,075.00 $0.00 Byron Rikert, Permit Review Timeline $0.00 Prorated $2,000.00 $2,000.00 $0.00 $2,000.00 $0.00 Byron Rikert Review Budget $0.00 Prorated $1,200.00 $1,200.00 $0.00 $1,200.00 $0.00 Byron Rikert Planning Phase $0.00 Prorated $1,200.00 $1,200.00 $0.00 $1,200.00 $0.00 Set of Plans $0.00 Prorated $1,200.00 $1,200.00 $0.00 $1,200.00 $0.00 Byron Rikert Review Plans $0.00 Prorated $2,800.00 $2,800.00 $0.00 $2,800.00 $0.00 City of Niagara Falls Develop Project $0.00 Prorated $2,000.00 $2,000.00 $0.00 $2,000.00 $0.00 Byron Rikert Schedule Application for $0.00 Prorated $800.00 $800.00 $0.00 $800.00 $0.00 Byron Rikert Building Permit Foundation Phase $0.00 Prorated $17,750.00 $17,750.00 $0.00 $17,750.00 $0.00 Locate Infrastructure $0.00 Prorated $720.00 $720.00 $0.00 $720.00 $0.00 On1Call [25%] Set Forms $0.00 Prorated $2,700.00 $2,700.00 $0.00 $2,700.00 $0.00 Shawn Dakin[75%], Forms[50] Excavation $0.00 Prorated $9,280.00 $9,280.00 $0.00 $9,280.00 $0.00 Subcontractor Lay Gravel $0.00 Prorated $2,250.00 $2,250.00 $0.00 $2,250.00 $0.00 Shawn Dakin[75%],Gravel[15] Install Rebar $0.00 Prorated $810.00 $810.00 $0.00 $810.00 $0.00 Rickert/Dakin, Rebar[100] Inspection $0.00 Prorated $400.00 $400.00 $0.00 $400.00 $0.00 City's Building Inspector Concrete $0.00 Prorated $1,590.00 $1,590.00 $0.00 $1,590.00 $0.00 LaForge Concrete[25%], Concrete[25] Structure Phase $0.00 Prorated $33,346.90 $32,466.90 $880.00 $25.00 $33,321.90 Erect and Frame Walls $0.00 Prorated $9,680.00 $8,800.00 $880.00 $0.00 $9,680.00 Rikert/Dakin, Nails, Hammers