A component in a music system has a life expectancy of 2,400 hours with a standard deviation of 300 hours. If an average person listens to music for 1,000 hours in a year, the probability that the component lasts for more than 3 years is
The answer to the math probability question you are presenting above would be .475 or (47.5%). The value of 3 years multiplied by 1000 would equal to 3000, thus the person will listen to music 3000 hours a year - which is two standard deviations than the mean. Following the empirical rule, the answer would be .475.
