please show formulas used and explain please

7. Mask-Up Davis's cost formulas appear in the table. What is Mask-Up Davis's activity variance with respect to mask materials? Fixed Per Month Mask Materials Employees Wages to sew the masks Utilities Rent Miscellaneous Cost Per Mask $4.00 $3.50 $0.50 $450.00 $1,300.00 $150.00 $0.30 Budgeted Masks for February Actual Masks Sold in February Actual Mask Materials in February Actual Employees Wages to sew the masks Actual Utilities Actual Rent Actual Miscellaneous 10,000 masks 12,000 masks $23,000 $25,000 $4,500 $1,400 $750 8. Using the table below, calculate the labor efficiency variance: Planned Masks to Produce in January 8,000 masks Standard Square Inches Per Cloth Mask 6 sq. inches Standard Price Per Square Inch $0.15 $ Standard Direct Labor Hours Per Mask 0.2 hours Standard Direct Labor Wage Per Hour $17 Actual Purchased Square Inches of Cloth 30,000 sq. inches Actual Square Inches of Cloth Still in Inventory at End of Jan. 5,000 sq. inches Actual Price Per Square Inch $0.14 Masks Produced in Jan. 6,000 masks Actual Direct Labor Hours Worked 1,500 hours Actual Direct Labor Cost $27,000