An orange grove has 675 orange trees. Three growers each checked 75 orange trees in different areas of the orchard and noted the number of trees that are ready for picking. Each grower used his or her results to estimate the total number of trees in the orchard that are ready for picking. Grower A noted that 11 orange trees were ready for picking. Grower B noted that 18 orange trees were ready for picking. Grower C noted that 13 orange trees were ready for picking. Using the information in the samples, what is a good estimate for the actual number of orange trees in the orchard that are ready for picking?