In 2008, Pfizer had 12,000 million shares of common stock authorized, 8,863 million in issue, and 6,746 million outstanding (figures rounded to the nearest million). Its equity account was as follows:

Common stock $443
Additional paid-in capital 70,283
Retained earnings 44,148
Treasury shares (57,391)

a.) What was the par value of each share?
b.) What was the average price at which shares were sold?
c.) How many shares had been repurchased?
d.) What was the average price at which the shares were repurchased?
e.) What was the net book value of Pfizer's common equity?