Coal is carried from a mine in West Virginia to a power plan

Coal is carried from a mine in West Virginia to a power plant in NewYork in hopper cars on a long train. The automatic hopper car loader isset to put 91 tons of coal into each car. The actual weights of coalloaded into each car are normally distributed, with mean μ=91 tons and standard deviation σ=3 ton.A) What is the probability that one car chosen at random will have less than 89.5 tons of coal?