In 2017, the entire fleet of light? duty vehicles sold in the united states by each manufacturer must emit an average of no more than 86 milligrams per mile (mg/mi) of nitrogen oxides (nox) and nonmethane organic gas (nmog) over the useful life ( 150,000 miles of driving) of the vehicle. nox + nmog emissions over the useful life for one car model vary normally with mean 80 mg/mi and standard deviation 4 mg/mi. (a) what is the probability that a single car of this model emits more than 86 mg/mi of nox + nmog? (enter your answer rounded to four decimal places.)