Sonya used to earn $25,000 a year selling real estate, but she now sells greeting cards. the return to entrepreneurship in the greeting cards industry is $14,000 a year. over the year, sonya bought $10,000 worth of cards from manufacturers and sold them 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 funds from her savings account. her bank pays 3 percent a year on savings accounts. at the end of the year, sonya was offered $1,600 for her cash register. calculate sonya’s explicit costs, implicit costs, and economic profit.