Calculator Technique Tutorial Series: z - score and z - table

The normal distribution, often called the bell curve, is one of the most important concepts in statistics and probability theory. It describes how data tends to be distributed around a central value, with most observations clustering near the mean and fewer appearing as you move further away. The curve is symmetrical, meaning the left and right sides are mirror images of each other. The spread of the distribution is measured by the standard deviation: a smaller standard deviation means the data