No, that is not the definition of a prior. There are priors which imply an expected number of buses, and priors that don’t. If you select a prior that doesn’t, you can still get a meaningful posterior distribution even if that posterior distribution doesn’t have a real-valued mean.
No, that is not the definition of a prior. There are priors which imply an expected number of buses, and priors that don’t. If you select a prior that doesn’t, you can still get a meaningful posterior distribution even if that posterior distribution doesn’t have a real-valued mean.