A recent stockholders' equity section ofAluminum Company of America (Alcoa)showed the following (in alphabetical order): additional paid-in capital $6,101, common stock $925, preferred stock $56, retained earnings $7,428, and treasury stock $2,828. (All dollar data are in millions.)

The preferred stock has 557,740 shares authorized, with a par value of $100 and an annual $3.75 per share cumulative dividend preference. At December 31 of the current year, 557,649 shares of preferred are issued and 546,024 shares are outstanding. There are 1.8 billion shares of $1 par value common stock authorized, of which 924.6 million are issued and 844.8 million are outstanding at December 31.

Compute the book value per share of common stock, assuming there are no preferred dividends in arrears.