In September, Carla Vista Industries sold 840 units of product. The average sales price was $50. During the month, fixed costs were $8,310 and variable costs were 70% of sales: (a) Determine the contribution margin in dollars, per unit, and as a ratio, (Round Contribution marsin to 0 decimal ploces, e.g. 5.275. Other all anwers to 2 decimal places, es. 52.75.) Contribution margin (in dollars) \$ $ Unit contribution margin Contribution margin ratio