The level of nitrogen oxides (NOX) in the exhaust of cars of a particular model varies Normally with mean 0.05 g/mi and standard deviation 0.01 g/mi.
A company has 25 cars of this model in its fleet. What is the level L such that the probability that the average NOX level x for the fleet is greater than L is only 0.01? Give your answer to 4 decimal places.
A company has 25 cars of this model in its fleet. What is the level L such that the probability that the average NOX level x for the fleet is greater than L is only 0.01? Give your answer to 4 decimal places.

P(Z > (L0.05)/(0.01/Sqrt25)) = 0.01
(L0.05)/(0.01/Sqrt25) = 2.33
(L0.05) = (0.01/5)*2.33
L = 0.0547g/m
(L0.05)/(0.01/Sqrt25) = 2.33
(L0.05) = (0.01/5)*2.33
L = 0.0547g/m