The results of CNN's 2008 presidential election poll are given in the table below. (Round your answers to four decimal places.)

Age of voterObamaMcCainOther/No Answer

18-2811.9%5.8%0.4%

30-4415.1%13.3%0.6%

45-6418.5%18.1%0.4%

65 and older 7.2%8.5%0.3%

(a) Find the probability that a voter is under 45, given that the voter voted for McCain.

(b) Find the probability that a voter is 45 or over, given that the voter voted for McCain.