Jake$$s Roof Repair provided the following data concerning its costs:

Fixed Cost per Month Cost per Repair$-$Hour

Wages and salaries $ $20,900$ $ $15\mathrm{.}00$

Parts and supplies $ $7\mathrm{.}50$

Equipment depreciation $ $2,760$ $ $0\mathrm{.}60$

Truck operating expenses $ $5,750$ $ $1\mathrm{.}60$

Rent $ $4,630$

Administrative expenses $ $3,890$ $ $0\mathrm{.}40$

For example, wages and salaries should be $$20,900$ plus $$15\mathrm{.}00$ per repair$-$hour. The company expected to work $2,800$ repair$-$hours in May but actually worked $2,700$ repair$-$hours. The company expects its sales to be $$49\mathrm{.}00$ per repair$-$hour.