Chris Ellis’s newsstand, just outside the Smithsonian subway station in Washington, DC, usually sells 120 copies of the Washington Post each day. Chris believes the sale of the Post is normally distributed, with a standard deviation of 15 papers. He pays 60 cents for each paper, which sells for $1.25. The Post gives him a 30-cent credit for each unsold paper. According to this given information optimal stocking out probability is %. (Do not round your intermediate calculations. Round your final answer to three decimal places. Only enter the number. For instance, if you find that probability is 0.5 then enter 50.)