The costs of publishing a grade school textbook can be assumed to be as follows. Use the date for questions 2 to 5. Fixed expenses for each new edition of the book: Copy editing $3,000 Art work $1,000 Typesetting $36,000 Variable expenses per copy of the book: Printing and binding $1.60 Bookstore discounts $2.00 Salespersons' commissions $0.25 Author's royalties $1.00 Each book sells for $10 per copy. The unit contribution margin for each copy of the book is: $5.15. $4.15. $5.40. $7.15.