An small commuter airport has 12 gates. Planes arrive at the airport, on average, every 5 minutes during the morning rush. This interarrival time is exponentially distributed. They "turn", on average, every 30 minutes. That is to say, that the aircraft is unloaded, groomed, and reloaded in 30 minutes. The standard deviation among turn-times is 10 minutes. What is the coefficient of variation of service time? Report your answer to the nearest second decimal place.