The amount of pollutants that are found in waterways near large cities is normally distributed with mean 9 ppm and standard deviation 1.7 ppm. 7 randomly selected large cities are studied. Round all answers to 4 decimal places where possible. a. What is the distribution of X? X - N( 9 ✓1.7 OF b. What is the distribution of a? N(9 ✓ 0.6425 03 0 c. What is the probability that one randomly selected city's waterway will have less than 9.3 ppm pollutants? d. For the 7 cities, find the probability that the average amount of pollutants is less than 9.3 ppm. e. For part d), is the assumption that the distribution is normal necessary? Yes No o f. Find the IQR for the average of 7 cities. Q1 = ppm Q3= ppm IOR: ppm