Question: Speed Limits. The speed limit on interstate 75 around Findlay, Ohio is 65mph. On a clear day with no construction, the mean speed of automobiles was measured at 63 mph with a standard deviation of 8mph. If the speeds are normally distributed, what percentage of the automobiles are exceeding the speed limit? If the highway patrol decides to ticket only motorist exceeding 72 mph, what % of motorist might they arrest?