Alain is a maintenance technician at a wind power plant, called a wind farm. There are 300 wind turbines on the wind farm. Alain’s team normally inspects about 5 turbines per day, but can inspect as many as 10. Sometimes they inspect a turbine but discover that no maintenance was actually needed. Typically, a turbine will need maintenance once every six months, but sometimes a turbine will become damaged and require emergency maintenance. Today Alain noticed a warning light on Turbine #147, an indicator that there is too much vibration in the turbine shaft. The sensors connected to the warning light are not perfectly reliable. Sometimes a turbine’s warning light will turn on for no reason at all; this happens about one day per year for each turbine, and nothing about his job is more annoying for him. Also, even if there is a problem with the turbine the warning light might fail to turn on; this happens 5% of the time when there actually is a problem with the turbine. Alain does not know when Turbine #147 was last maintained. Should Alain believe that Turbine #147 needs maintenance today?
I don't know where to even start, please give me some clues.
I don't know where to even start, please give me some clues.