Standard normal distribution has a mean of 0 and a standard deviation of 1. The standard deviation is simply how spread out the numbers are so the further the data point is from the mean, the less likely it is to occur. The characteristics of standard normal distribution is that it is symmetrical around its center and mirrors on the right and left side. There is also one mode (peak) of the curve. The tails of the curve never touch the x axis. I think that education would follow normal distribution in this example because if HR pulls the files and plot employees education, it'll fall within standard deviation. The other categories would be too spaced out because they have too much of a wide range to plot and fall within normal distribution. The other categories would look more like a scatter plot.