Sales cost of sales industry averages
new course books $ 1,086,800 $ 742,567 25.4
used course books 468,200 318,222 32.6
custom published books 212,222 159,293 25.6
textbook rental sales 102,323 90,323 22.1
course technology 90,600 80,432 11.2
trade books 68,400 40,356 24.3
professional reference books 22,330 15,200 31.0
total book sales $2,050,875 $1,446,393 26.5
total non-book sales $823,578 $612,233 29.7
total net sales $2,874,453 $2,058,626 28.3

(a) calculate the gross margin percentage for each of state university’s product lines.
(b) compare state university’s gross margins to industry averages. indicate any margins that appear out of line, in relation to the industry