9 In 2011, Toni taught music and earned £20,000. She also earned £4,000 by renting out her basement. On 1 January 2012, she quit teaching, stopped renting out her basement and began to use it as the office for her new website design business. She took £2,000 from her savings account to buy a computer. During 2012, she paid £1,500 for the lease of a Web server and £1,750 for a high-speed Internet service. She received a total revenue from website designing of £45,000 and earned interest at 5 per cent a year on her savings account balance. Normal profit is £55,000 a year. At the end of 2012, Toni could have sold her computer for £500.

Calculate Toni’s opportunity cost of production and her economic profit in 2012.