Blue Spruce inc makes unfinistied bookcases that it sells for $57. Production costs are $38 variable and $10 fixed. Because it has unused capacity, Blue Spruce is considering finisting the bookcases and selling them for $73. Variable finishing costs are expected to be $8 per unit with no increase in foxed costs. Prepare an analysis on a per-unit basis that shows whether Blue Spruce should sell unfinished or finished bookcases. (If an amount reduces the net income then enter with a negative sign preceding the number, e.g, 15,000 or parenthesis, e.g, (15,000)