Suppose the going rate (i.e., the price) for a room at Hotel Madison is $50 per night. At that price, the hotel has an average of 40 occupants per night. After raising the rate to $150, this average decreases to 10 occupants. What is the elasticity of demand for hotel rooms at these rates? If necessary, round your answer to the nearest tenth and include leading zeros in a decimal. (That is, if you find an answer of 0.932, type "0.9").