What happens when continuous data fails the Normality test? There is hope. There is an alternative -- nonparametric tests to the rescue! When comparing means using t-tests and ANOVA is not possible, use nonparametric tests to compare medians. Learn to compare medians using Minitab. Learn to run the 1-sample Wilcoxon, Mann-Whitney, and Kruskal-Wallis tests with Minitab.
- [Voiceover] In this movie I will show you…how to compare medians using nonparametric tests.…Open exercise file 04-05.…Here we have three data sets.…These could be processing times…of three offices, A, B, and C.…Let's say I want to compare the median of A…to a target value, 70.…To do that I can run a one sample Wilcoxon test.…Go up to Stat, Nonparametrics, One Sample Wilcoxon,…select A, and my testing is a median target of 70…in our example, whether it's equal to…or not equal to, that's our hypothesis.…
Okay, and here we have the prinout from the Wilcoxon test…with a P value of 0.654, which is great that it's 0.05,…therefore we failed to reject the null hypothesis.…So we can see that a test median…and a median of A are equal.…What if I want to compare two offices, A versus C.…Are they equal or not?…To compare these two medians, I can run a Mann-Whitney test.…Go up to Stat, Nonparametrics, Mann-Whitney.…
The first sample is A, second sample is C,…and all for 0.05 or 95% confidence level,…not equal is fine, OK, and here we have the printout…
Dr. Richard Chua shows how to import and organize data; open, save, and share Minitab worksheets and projects; create graphs and charts; and use descriptive statistics and statistical tests in Minitab to make inferences and data-driven decisions. Then learn how to make inferences on continuous data—running normality tests, variance tests, correlations, and simple regression tests. Finally, discover how to share your findings with others using reports and simple copy-and-paste techniques. Start watching to learn why Minitab is one of the world's most popular statistical software tools.
- Inputting data in Minitab
- Creating display graphs and charts, including bar and Pareto charts and scatterplots
- Describing data with statistics
- Comparing variance, multiple means, and medians
- Running multiple regression tests
- Comparing proportions
- Saving worksheets and Minitab projects
- Sharing your work and generating reports