How are state taxes determined if you lived in 3 states during one year?

Generally, when moving out of California, you will remain a California resident until you establish a permanent residency in another state.  Therefore in your circumstance, since you lived in NJ for 3 months only as a transitory/temporary period, you would still be considered a resident of California until you permanently moved to PA, at which time, you would be a PA resident.

ok, thanks.