In a certain country, a letter up to 1 ounce requires postage in the amount of 0 point 4 2 dollars , and each additional ounce (or fraction of an ounce) has an additional cost. The function represents the cost of mailing one letter with a weight of x ounces in this country. f of x is equal to 0 point 4 2 plus 0 point 2 0 lceil x minus 1 rceil Josiah has two letters. The first weighs 2 point 9 ounces, and the second weighs 4 point 1 ounces. What is the total amount Josiah can expect to pay for postage?