Worldwide quarterly sales of a brand of cell phones was approximately

q = −p + 176 million phones when the wholesale price was $p.
(a) If the cellphone company was prepared to supply q = 9p − 344 million phones per quarter at a wholesale price of $p, what would be the equilibrium price? $52

(b) The actual wholesale price was $47 in the fourth quarter of 2004. Estimate the projected shortage or surplus at that price.
Shortage.
I can't find the exact amount of shortage, I don't know how.

Thank You