Richard Miller recently fulfilled his long-time dream of opening a gym that offers spinning exercise classes for $10 per person. To differentiate his gym and better serve his clients, Richard provides a towel, a bottle of water, and an after-workout protein shake to each person participating in a class, at a cost of $1.81 per person. Richard employs four part-time instructors and pays them each $1,600 per month. He also pays himself a monthly salary of $6,100. Richard's other monthly costs are $2,100 for rent, $1,550 for depreciation on his 30 bikes, and $1,550 in utilities and insurance. (a) What is Richard's contribution margin per unit? (Round answer to 2 decimal places, eg. 52.75.) Contribution margin $ per unit (b) What is Richard's contribution margin ratio? (Round answer to 2 decimal places, eg. 52.75) Contribution margin ratio