Sonya used to sell real estate and earn $25,000 a year, but now she sells greeting cards. Normal profit for the retailers of greeting cards is $14,000. Sonya used 4,000 of her savings to start her business. Over the past year, Sonya bought $10,000 worth of cards from manufacturers of cards. She sold these cards for $58,000. Sonya rents a shop for $5,000 a year and spends $1,000 on utilities and office expenses. Sonya owns a cash register, which she bought for $2,000 with part of her savings account money. Her bank pays 3% a year on savings accounts. She calculated her entrepreneurial income to be worth $500.

1. Calculate Sonya's:
2. Explicit costs
3. Implicit costs
4. Economic profit