need help figuring out the last step

Spray drift is a constant concern for pesticide applicators and agricultural producers. The inverse relationship between droplet size and drift potential is well known. The paper "Effects of 2,4-D Formulation and Quinclorac on Spray Droplet Size and Deposition"t investigated the effects of herbicide formulation on spray atomization. A figure in a paper suggested the normal distribution with mean 1050 pm and standard deviation 150 pm was a reasonable model for droplet size for water (the "control treatment") sprayed through a 760 ml/min nozzle. (a) What is the probability tha less than 1470 pm at least 950 pm 0.9974 0.7486 the size of a single droplet is less than 1470 um? At least 950 pm? (Round your answers to four decimal places.) v v (b) What is the probability that the size of a single droplet is between 950 and 1470 pm? (Round your answer to four decimal places.) 0.746| (c) How would you characterize the smallest 2% of all droplets? (Round your answer to two decimal places.) The smallest 2% of droplets are those smaller than |742.50 Hmin size. (d) If the sizes of five independently selected droplets are measured, what is the probability that at least one exceeds 1470 pm? (Round your answer to four decimal places.) 0.0129] %