Sampling distribution of the mean and confidence intervals 4. Sampling distribution of the mean: The concentration of NOx (a set of criteria pollutants) in Los Angeles County has the following characteristics: µ = 700 ppm, σ = 30 ppm. a. If you take 30 additional air samples, what is the probability that your sample mean will be greater than 710 ppm? Report 2 significant figures. % b. Discuss how increasing the sample size from 30 to 50 would affect the probability of the sample mean exceeding 710 ppm. What implications does this have for the accuracy of environmental monitoring? The probability would: O Increase Implications for environmental monitoring: O Decrease