Luke sells for the Flat Company of Downtown. An analysis of the performance of the company's 25 person sales force shows that the average sales rep works 250 days a year, makes four calls a day, obtains an order, averaging $15,000, every ten calls made. Luke worked 200 days last year during which she made a total of 700 calls which resulted in 50 orders totaling $1,500,000 in sales volume. What was Luke's average order size?