Sales before tax=4455.28/1.085=$4106.25. This assumes that tax is added to gross sales making the net sales higher than the gross sales.
However, gross sales usually come before tax and if the sales are taxed there will be a reduction of 8.5% giving net sales. If gross sales are $4455.28 and tax is to be paid, then net sales=4455.28-(8.5% of 4455.28)=4455.28×0.915=$4076.58.