This is shown below. If your data is not approximately distributed as the above, you may not want to declare your data is normal. You can use a graphical Probability Plot or a statistical test ...

The figure above showed two normal distributions. You can now see these are probability density function (PDF) plots. If we re-plot the exact same distribution as a cumulative distribution ...

you decide to check whether the diameters are normally distributed. The following statements create the normal probability plot shown in Figure 9.1: title 'Normal Probability Plot for Diameters'; proc ...

is a probability distribution that appears as a "bell curve" when graphed. The normal distribution describes a symmetrical plot of data around its mean value, where the width of the curve is ...

Normal Distribution: a distribution with density function . It is bell-shaped and symmetric, and is very common in "real life". Normal Probability Plot: a quantile-quantile plot where one of the data ...