View Policies Current Attempt in Progress The life of a semiconductor laser at a constant power is normally distributed with a mean of 7000 hours and a standard deviation of 600 hours. a) What is the probability that a laser fails before 5300 hours? Round your answer to four decimal places (e.g. 98.7654). P = i b) What is the life in hours that 90% of the lasers exceed? Round your answer to the nearest integer (e.g. 9876). X= i h c) What should the mean life equal for 99% of the lasers to exceed 10000 hours before failure? Round your answer to the nearest integer (e.g. 9876). # = h d) A product contains three lasers, and the product fails if any of the lasers fails. Assume the lasers fail independently. What should the mean life equal for 99% of the products to exceed 10000 hours before failure? Round your answer to the nearest integer (e.g. 9876). i h Save for Later Attempts: 0 of 1 used Submit