Suppose Marv, the owner-manager of Marv's Hot Dogs, earned $72,000 in revenue last year. Marv's explicit costs of operation totaled $36,000.

Suppose Marv, the owner-manager of Marv's Hot Dogs, earned $72,000 in revenue last year. Marv's explicit costs of operation totaled $36,000. Marv has a Bachelor of Science degree in mechanical engineering and could be earning $30,000 annually as mechanical engineer.