Not all statistics are the same. It’s useful to discern between the various types of statistics when doing analysis.
One Sample T Hypothesis Test (Student’s T Test) are used to resolve hypothesis tests around comparing process means ( sample size to be <30)
The F-distribution, also known Fisher-Snedecor distribution, is used to test for equality of variances from two normal populations.
A bi-modal distribution has two modes. In other words, outcome of two processes with different distributions are combined in one set of data.
Specification limits are set by the customers; often, Voice of the Customer is referred to as the customer specification limits.