Can some one help me solve this problem please.
Information provided:

Egret Corp is a wholesaler that sells a single product and maintains a stable cost structure. Management has provided the following data for two months

May June

Sales Revenue $577,500 $1,155,000
Gross Margin $364,700 $ 854,700
Net Operating income(loss)$(39,000) $ 422,700
Selling price per unit $ 165 $ 165

Suppose the price remains the same. The best estimate of the margin of safety in July at the sales volume below is:
Sales volume in July: 6,500 units