I have a question that is asking how far a muon neutrino of 1 GeV will travel in the atmosphere is the muon lifetime is $2.2\mu$ sec. This is in the context of muons being created by cosmic rays hitting the atmosphere. I know that when cosmic rays hit the atmosphere they create pions which mostly decay into muons and muon neutrinos, so I'm assuming that since it's giving the lifetime of the muon itself it only wants me to consider the distance traveled by a daughter muon neutrino from the decay of the muon.
How do I calculate this?
Edit: I have a theory that I need to calculate the lifetime of the muon neutrino, then calculate the distance it travels using relativity (time dilation), but I'm not sure how I factor in the lifetime of the muon into this.