Soybeans are an important source of oil and protein and are also used to produce many food additives. The leading producers of soybeans are the United States, Brazil, Argentina, and China. The first genetically modified (GM) soybeans were grown in the United States in 1996, and now GM soybeans are grown in at least nine countries. Independent random samples of soybean farmers in the United States and Brazil were obtained, and the number growing GM soybeans was recorded. The data are given in the following table.
a. Find the sample proportion of GM soybean farmers for each country. Verify the nonskewness criterion.
b. Conduct the appropriate hypothesis test to determine whether there is any evidence that the true proportion of GM soybean farmers in the United States is 0.15 greater than in Brazil. Use a 5 0.05.
c. Find the p value associated with this hypothesis test.