At December 31, 2017, the balance sheet of Meca International included the following shareholders' equity accounts: Shareholders' Equity ($ in millions) Common stock, 80 million shares at $1 par Paid-in capital-excess of par Paid-in capital-share repurchase Retained earnings $80 440 Assuming that Meca International retires shares it acquires and the following transactions occurred during 2018. On February 12, 2018, Meca reacquired 1 million common shares at $14 per share. On June 9, 2018, Meca reacquired 2 million common shares at $11 per share. On July 25, 2018, Meca sold 2 million treasury shares at $17 per share-determine cost as the weighted average cost of treasury shares. The balance of retained earnings account at December 31, 2018 is $533.5 million $550 million $556.5 million $543.5 million