According to a government study among adults in the 25- to 34-year age group, the mean amount spent per year on reading and entertainment is $1,999. Assume that the distribution of the amounts spent follows the normal distribution with a standard deviation of $574.
(a) What percent of the adults spend more than $2,550 per year on reading and entertainment?
(b) What percent spend between $2,550 and $3,200 per year on reading and entertainment?
(c) What percent spend less than $1,100 per year on reading and entertainment?