For Exercises 1–4, perform the goodness of fit test.
1. Truck-Hauled Trade. According to the U.S. Census Bureau, 32% of North American international truck-hauled trade (in dollars) goes from the United States to Canada, 22% goes from the United States to Mexico, 31% goes from Canada to the United States, and 15% goes from Mexico to the United States. Suppose that a new survey showed that $25 billion went from the United States to Canada, $15 billion went from the United States to Mexico, $20 billion went from Canada to the United States, and $10 billion went from Mexico to the United States. Test whether the population proportions of truck-hauled trade have changed, using level of significance .
11.99.1
, , , . : The random variable does not follow the distribution specified in . billion, billion, billion, billion. Since none of the expected frequencies is less than 1 and none of the expected frequencies is less than 5, the conditions for performing the goodness of ft test are met. Reject if -value . . -value . Since -value is not , we do not reject . There is insufficient evidence that the population proportions of truck-hauled trade have changed.