An ornithologist uses GPS data to model the average speed of a bird migrating along a circular route of 1,200 km. The bird flies at 60 km/h for the first 400 km, then slows to 40 km/h for the next 600 km due to weather, and accelerates to 80 km/h for the final 200 km. What is the bird’s average speed for the entire journey? - Crosslake