help with question 7

The owner of a sales kiosk of perishable goods downloaded 10 weeks of sales data from her POS (point of sales) system. That appears below. The unit revenue is $65, the unit cost is $28, and any unsold inventory at the end of each day is sold on the secondary market at a salvage price of $9 per unit. Restocking occurs on a daily basis. An inventory stockout on any given day sets the maximum revenue for that day, since replenishment orders cannot be placed for delivery on the same day. The daily fixed cost of operation is $160. Data Ten Week Sales Data (Units) \begin{tabular}{|r|} \hline BIN \\ \hline 10 \\ \hline 11 \\ \hline 12 \\ \hline 13 \\ \hline 14 \\ \hline 15 \\ \hline 16 \\ \hline 17 \\ \hline 18 \\ \hline 19 \\ \hline 20 \\ \hline \end{tabular} At what average daily demand will the business be at breakeven. (At the optimum stocking level.) Enter your result rounded to one decimal place