The lifetime of a certain type of battery is normally distributed with mean value 12 hours and standard deviation 1 hour. there are nine batteries in a package. what lifetime value is such that the total lifetime of all batteries in a package exceeds that value for only 5% of all packages? (round your answer to two decimal places.)

The probability that a normally distributed dataset with a mean, μ, and statndard deviation, σ, exceeds a value x, is given by



Given that the lifetime of a certain type of battery is normally distributed with mean value 12 hours and standard deviation 1 hour and that the probability that nine batteries in a package exceeds a certain value, x, is 5% or 0.05. Then the value x is given by