Cadavieco Detalling's cost formula for its materials and supplles is $2,020 per month plus $7 per vehicle. for the month of November, the company planned for activity of 97 vehicles, but the actual level of activity was 57 vehicles. the actual materials and supplles for the month was $2,530. The activity variance for materials and supplies in November would be closest to: $280 F $ 169 F $169 U $280 U