REVIEW FROM CHAPTER 6: As passenger aircraft ages U.S. Air has a maintenance plan that will discontinue using old aircraft, specifically those that are in the top 5% of the ages of the aircraft Of the current aircraft, the mean age is 13.41 years and the standard deviation is known to be 5.2 years. Find the cut-off age for the top 5% of aircraft. (Round answer to 10ths of a year.)