A longitudinal fin with b=30 cm is made of aluminum (k=237 W/(m-K)) and has a base temperature of 80oC. The fin cross-sectional area is 7.85 × 10-5 m2 and the perimeter is 3.14× 10-2 m. The ambient temperature is 22 oC with a heat transfer coefficient of 11 W/(m2-K). If the fin's tip is insulated, what is the fin efficiency?