Pine Street Inc. makes unfinished bookcases that it sells for exist57.41. Production costs are exist37.50 variable and exist9.99 fixed. Because it has unused capacity, Pine Street is considering finishing the bookcases and selling them for exist74.67. Variable finishing costs are expected to be exist8.31 per unit with no increase in fixed costs. Prepare an analysis on a per unit basis showing whether Pine Street should sell unfinished or finished bookcases. (Round answers to 2 decimal places, e.g. 15.25. Enter negative amounts using either a negative sign preceding the number e.g. -45 or parentheses e.g. (45).) The bookcases