Tag: normal distribution

When someone says your data is skewed, do you get upset? Skewness can be a natural state of your data. Let’s find out more about skewness and what it means.

The word Normal generally has a positive connotation. When applied to statistics, the term Normal Distribution has essentially the same effect. Let’s see why. 

Is your data normal? Oh no! Is that a problem? The concept of data normality can be important when using certain statistical tools to make data-driven decisions.

The distribution of data can be categorized in two ways: normal and non-normal. If data is normally distributed, it can be expected to follow a certain pattern in which the data tend to be around a central value with no bias left or right (Figure 1). Non-normal data, on the other hand, does not tend […]

The process capability indices Pp and Cp describe how closely a process can operate within its specification limits. Many articles describe the difference between Pp and Cp simply: one is short term, one is long term. Moving beyond such a description, this article focuses on the untapped power of capability analysis and shows you how […]

Z score is a measure of the distance in standard deviations of a sample from the mean. It is calculated as (X – X bar) / sigma. The table of z distribution is shown below. Table of the Standard Normal (z) Distribution z 0.00 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.0 0.0000 […]