Final answer:
The group's contribution margin per unit is $60, calculated by subtracting the variable cost per procedure ($22) from the revenue per procedure after an 18 percent discount ($82).
Step-by-step explanation:
The contribution margin per unit is calculated by taking the revenue per procedure and subtracting the variable cost per procedure. In the given scenario, the charge per procedure is $100, and with an 18 percent discount, the actual revenue per procedure becomes $82 ($100 - $18). To find the contribution margin per unit, we subtract the variable cost per procedure, which is $22, from the adjusted revenue per procedure:
Contribution margin per unit = Revenue per unit after discount - Variable cost per unit
Contribution margin per unit = $82 - $22
Contribution margin per unit = $60
Thus, the group's contribution margin per unit is $60.