As a project for their high school mathematics class, four class members purchase packages of a leading breakfast cereal for subsequent weighing and comparison with the 12-ounce label weight. The students are surprised when they weigh the contents of their four packages and find the average weight to be only 11.5 ounces. When they write to the company, its consumer relations representative explains that “the contents of the ‘12- ounce’ packages average 12.2 ounces and have a standard deviation of 0.4 ounces. The amount of cereal will vary from one box to the next, and your sample is very small—this explains why your average weight could be just 11.5 ounces.” If the spokesperson’s information is correct, how unusual would it be for these students to get a sample mean as small as the one they obtained? Be sure to state any assumptions you have made in obtaining your answer.
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