Commodities shipped by rail. The following table, extracted from Railway Age (May 1999), lists the number of carloads of different types of commodities that were shipped by the major U.S. railroads during a week. Suppose the computer record for a carload shipped during the week is randomly selected from a masterfile of all carloads shipped that week and the commodity type shipped is identified.
Type of Commodity Number of Carloads Agricultural products 41,690 Chemicals 38,331 Coal 124,595 Forest products 21,929 Metallic ores and minerals 34,521 Motor vehicles and equipment 22,906 Nonmetallic minerals and products 37,416 Other carloads 14,382 Total 335,770 Source: Railway Age, May 1999, p. 1.
List or describe the sample points in this experiment. Find the probability of each sample point. What is the probability that the railcar was transporting automobiles? Nonagricultural products? What is the probability that the railcar contained chemicals or coal? One of the carloads shipped that week was in a boxcar with serial number 1003642. What is the probability that this particular carload would be the one randomly selected from the computer file? Justify your answer.