What Are We Testing? Refer to the sample data in Exercise 1. A...

Question

What Are We Testing? Refer to the sample data in Exercise 1. Assuming that we use the Wilcoxon rank-sum test with those data, identify the null hypothesis and all possible alternative hypotheses.

Accepted Answer

Hello there. Today we're going to solve the following practice problem together. So first off, let us read the problem and highlight all the key pieces of information that we need to use in order to solve this problem. Researchers are comparing the effectiveness of two medications in reducing blood pressure because the data are skewed, they use the man-Whitney U test. What is the null hypothesis and what alternative hypothesis could be considered? Awesome. So it appears for this particular prom we're ultimately asked to solve for two separate answers. We're asked to determine for this particular problem. What is the null hypothesis? That's our first answer. And our second answer is we're asked to determine what is the alternative hypothesis that could be considered for this particular problem. So now that we know what we're ultimately trying to solve for, We need a note, first off, we need to recall a note that the man Whitney U test, as we should recall, this is our first major step. We need to note and recall that once again the man Whitney U test compares the distributions of two independent samples, especially when the data is not normally distributed. Awesome, so let us know and we'll call this the M. WU for short, so the man Whitney U test. I'll add a T so you know. So the man-Whitney U test once again compares the distributions of two independent samples, especially when the data is not, not normally distributed. So, second step that we need to consider is we need to recall and note that the null hypothesis, which you'll call NH for short, the null hypothesis states that the two medications will result in the same distribution of blood pressure reductions. Thirdly, Let us note that, as we should recall, for this particular case, the alternative hypothesis can be two-tailed. Where the distributions are different, or one tail where one medication leads to greater or lesser reductions. So, fourthly, our 4th and final step, we need to note that the null hypothesis will result in the two medications resulting in the same distribution of blood pressure reductions. And as for the alternative hypothesis, the distributions will be different. One medication will lead to greater or lesser reductions. So therefore, with all these pieces of information in mind, our final pair of answers without a doubt, have to be the following. So the null hypothesis, the two medications result in the same distribution of blood pressure reductions, and the alternative hypothesis, the distributions differ. One medication leads to greater or lesser reductions in blood pressure. And that's it. We've officially solved for this problem. Thank you so much for watching. Hopefully that helped, and I can't wait to see you in the next video. Bye.

What Are We Testing? Refer to the sample data in Exercise 1. Assuming that we use the Wilcoxon rank-sum test with those data, identify the null hypothesis and all possible alternative hypotheses.

Key Concepts

Wilcoxon Rank-Sum Test

Null Hypothesis

Alternative Hypothesis

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