Of the four Scales of measurement (Nominal, Ordinal, Interval, and Ratio), Ratio scales are ideal for Six Sigma projects.
We use confidence intervals to determine the degree of certainty that the sample group accurately represents the entire population.
A Paired T Distribution, Paired T-Test, Paired Comparison test, and Paired Sample Test compares the mean & standard deviation of two groups.
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)