Night Shades Inc. (NSI) manufactures biotech sunglasses. The variable materials cost is $1.99 per unit, and the variable labor cost is $4.18 per unit. a. What is the variable cost per unit? :I b. Suppose the company incurs fixed costs of $500,000 during a year in which total production is 325,000 units. What are the total costs for the year? :I