You can estimate a tree's age in years by using the formula a=r/w, where r is the tree's radius without bark and w is the average thickness of the tree's rings. The circumference of a white oak tree is 100 inches. The bark is 0.5 in. thick, and the average thickness of a ring is 0.2 in. Estimate the tree's age enclosed by the outher circumference of the widest ring.
