Fast food restaurants devote a lot of effort studying the amount of time cars spend in their drive-throughs. Obviously, the faster cars get through the drive-through, the more opportunity for making money. A study of fast-food drive-through times found that Wendy's had the best time, with mean time spent in their drive-through of 138.5 seconds. Assuming drive-through times are normally distributed with a standard deviation of 29 seconds: