Animal Migrations

If wolves are currently migrating into the forest, there is a 90% chance that the next migration will also be by wolves, and a 10% chance that it will be by bears. However, if bears are the migrators, there is a 60% chance that the next migration will also be by bears, and a 40% chance that it will be by wolves. On average, how many migrations will occur before the next wolf migration occurs?

Answer format: round to 2 decimal places.