Lorenzo operates a car wash. Incoming cars are put on an automatic conveyor belt. Cars are washed as the conveyor belt carries them from the start station to the finish station. After a car moves off the conveyor belt, it is dried manually. Workers then clean and vacuum the inside of the car and are paid per car. Depreciation is calculated on a straight line basis.

Lorenzo washed $80000$ cars in $2018$ and reported the following costs:

Account description Costs

Car wash labour R$260000$

Soap, cloth and supplies R$42000$

Water R$38000$

Electric power to move the conveyor belt R$72000$

Depreciation R$64000$

Salaries R$46000$

Required:

$1\mathrm{.}1$ Classify each account as variable or fixed with respect to the number of cars washed. Give a brief explanation for your answer. $(12)$

$1\mathrm{.}2$ Suppose Lorenzo washed $90000$ cars in $2019.$ Use the cost classification you developed in $1\mathrm{.}2$ above to estimate Lorenzo$$s total costs in $2019.(5)$