On January 1, 20X7, Pisa Company acquired 80 percent of Siena Company by purchasing 40,000 shares of Siena's common stock. There was no differential related to this transaction. The noncontrolling interest had a fair value equal to 20 percent of book value. The book value of Siena on December 31, 20X7 was as follows: On January 1, 20X8, Siena sold an additional 12,500 shares to a nonaffiliate for $25 per share. What is Pisa's new ownership interest? One of the answers below.

84 percent 55 percent 70 percent 64 percent