"Black Friday" is the day after Thanksgiving and the traditionalfirst day of the Christmas shopping season. Suppose a recent pollsuggested that 66% of Black Friday shoppers are actually buying forthemselves. A random sample of 130 Black Friday shoppers isobtained. Answer each problem using the normal approximation to thebinomial distribution.
(a)
Find the approximate probability that fewer than 73 Black Fridayshoppers are buying for themselves. (Round your answer to fourdecimal places.)
(b)
Find the approximate probability that between 74 and 84(inclusive) Black Friday shoppers are buying for themselves. (Roundyour answer to four decimal places.)