To find the total distance the class traveled, you need to add the distance traveled by train and the distance traveled by bus.
Distance by train: 9.22 kilometers
Distance by bus: 8.6 kilometers
Total distance = Distance by train + Distance by bus
Total distance = 9.22 km + 8.6 km
Total distance = 17.82 km
The class traveled a total of 17.82 kilometers.