Coal is carried from a mine in West Virginia to a power plant in New York in
Question:
Coal is carried from a mine in West Virginia to a power plant in New York in hopper cars on a long train. The automatic hopper car loader is set up to put 36 tons of coal in each car. The actual weights of coal loaded into each car are normally distributed with a mean =36 tons and a standard deviation =0.8 tons.
A) What is the probability that one car chosen at random will have less than 35.5 tons of coal?
B) What is the probability that 20 cars chosen at random will have a mean load wait less than 35.5 tons of coal?
C) Suppose that the weight of coal in one car was less than 35.5 tons. Would that fact make you suspect that the loader had slipped out of adjustment? Suppose the weight of coal and 20 cars selected at random hadn't average less than 35.5 tons. Would that fact make you suspect that the loader had slipped out of adjustment? Why? Show formula used
Understanding Basic Statistics
ISBN: 978-1111827021
6th edition
Authors: Charles Henry Brase, Corrinne Pellillo Brase