1. Suppose that the longevity of a light bulb is exponential with a mean lifetime of seven years. (a)Sixty percent of all light bulbs last at least how long? (Round your answer to two decimal places.)
2. At an urgent care facility, patients arrive at an average rate of one patient every nine minutes. Assume that the duration between arrivals is exponentially distributed. (Round your answers to four decimal places.)(a)If 10 minutes have passed since the last arrival, what is the probability that the next person will arrive within the next nine minutes?
3. Find the maximum of x in the bottom quartile. (Round your answer to four decimal places.)X ~ N(8, 9)
4. The life of Sunshine CD players is normally distributed with a mean of 4.1 years and a standard deviation of 1.3 years. A CD player is guaranteed for three years. We are interested in the length of time a CD player lasts. Find the probability that a CD player will last between 2.8 and seven years (.b) Give the probability statement and the probability. (Enter exact numbers as integers, fractions, or decimals for the probability statement. Round the probability to four decimal places.) P( < x < ) =
5. The patient recovery time from a particular surgical procedure is normally distributed with a mean of 5.4 days and a standard deviation of 2.1 days. What is the 75th percentile for recovery times? (Round your answer to two decimal places.) days