Suppose that shoe sizes of American women have a bell-shaped distribution with a mean of 8.33 and a standard deviation of 1.48. Using the empirical rule, what percentage of American women have shoe sizes that are at least 12.77?
8.33 + 3 S.D == 8.33 + 3 (1.48) = 12.77
(not sure what the 'empirical rule' is...but see the usual bell curve graph below)
3 standard deviations above the mean encompasses nearly 100% of all women (99.7 %)
so 99.7% of women have a shoe size 12.77 OR LESS
which I think means only .3% have a shoe size of 'at least' 12.77..... ( question is worded oddly)