can the population variance never be estimated? why can't we always have a range in the population can variance be compared to a normal distribution? can we never have a normal distribution can we always have a normal distribution of the population can we never have a normal distribution can we never have a normal distribution what is the difference between a normal and a t distribution can we never have a normal distribution can we never have a normal distribution? how are distributions determined can we never have a normal distribution can we never have a normal distribution can we always have a normal distribution can a variance be never expected can you never have a normal distribution can we never have a population variance can you have a regular distribution can we never have a normal distribution why do we never have a normal distribution