Shelly owns a bookstore, where she earns all of its accounting profits in addition to a $30,000 a year salary she pays herself. Last year, her bookstore's accounting profit was $50,000. Shelly has a standing offer of $35,000 a year to write for Penguin Publishing, and if she had invested her capital outside her company, she would have earned $22,000 that year.

5. What was Shelly's economic profit?