Researchers have developed a new precooling method for preparing Florida vegetables for market. The system employs an air and water mixture designed to yield effective cooling with a much lower water flow than conventional hydrocooling. To compare the effectiveness of the two systems, 20 batches of green tomatoes were divided into two groups; one group was precooled with the new method, and the other with the conventional method. The water flow (in gallons) required to effectively cool each batch was recorded.

a. Identify the population, the samples, and the type of statistical inference to be made for this problem.

b. How could the sample data be used to compare the cooling effectiveness of the two systems?