Just an observation: it is possible for the data to be normally distributed with a mean higher than 3, that just means that the distribution is truncated closer

Just an observation: it is possible for the data to be normally distributed with a mean higher than 3, that just means that the distribution is truncated closer to the median on the upper tail than the lower one. However, just from eyeballing his chart the data in this case do appear to be slightly left-skewed.