Surprise Headliner

The pop star Nova Quinn is rumored to close this year's Harborlight Festival, which takes place in Porto, but nobody knows where she currently is. Based on her tour schedule there is a 90% chance she is in Lisbon and a 10% chance she is in Porto. If she is in Porto, there is a 55% chance she will show up and perform; if she is in Lisbon, there is a 5% chance she will make the trip and perform. Given that Nova Quinn ends up performing at the festival, what is the probability that she travelled in from Lisbon? Give the exact value as a decimal or fraction.