<span>The question asks to find what percent of the total cost was the price of the file set. Total cost was: $62 + $9 + $4 = $75. Now the total cost ( $75 ) represents 100% and the price of the file set ( $9 ) represents x %. When we make a proportion - 75 : 9 = 100 : x. 75 x = 9 * 100, 75 x = 900; x = 900 : 75; x = 12%. Answer: The file set was 12% of the total cost.</span>
