Suppose that the lifetimes of TV tubes are normally

Last updated: 7/9/2022

Suppose that the lifetimes of TV tubes are normally distributed with a standard deviation of 1.2 years. Suppose also that exactly 35% of the tubes die before 4.5 years. Find the mean lifetime of TV tubes. Carry your intermediate computations to at least four decimal places. Round your answer to at least one decimal place.