Think what they are really looking for is how you interact with the others in the group in a given situation. If everyone else in the group takes the back seat then taking the helm is essential to complete the task. Perhaps ask at the beginning 'Does anyone has any ideas?'. But in order not to seem like a dictator once you've made a suggestion ask the group if they are in agreement, or whether anyone else has a method which they may think is better.
Hope this is right! The general idea being; steer, but don't be overbearing and be receptive to everyone's ideas.
Good luck mate!