A horticulturist is measuring the vitamin C concentration in oranges in an orchard on a research farm in south Texas. He is interested in the variation in vitamin C concentration across the orchard, across the productive months, and within each tree. He divides the orchard into eight sections and randomly selects a tree from each section during October– May, the months in which the trees are in production. During each month, he selects from each of the eight trees 10 oranges near the top of the tree, 10 oranges near the middle of the tree, and 10 oranges near the bottom of the tree. The horticulturist wants to monitor the vitamin C concentration across the productive season and determine if there is a substantial difference in vitamin C concentration in oranges at various locations in the tree.