'Suppose that the mean retail price per gallon of regular grade gasoline in the United States is $3.49 with a standard deviation of $0.10 and that the retail price per gallon has a bell* shaped distribution. (a) What percentage of regular grade gasoline sold between $3.39 and $3.59 per gallon? E% (b) What percentage of regular grade gasoline sold between $3.39 and $3.69 per gallon? |:|% (c) What percentage of regular grade gasoline sold for more than $3.69 per gallon? |:|%