How to State the Conclusion about a Hypothesis Test

After you have completed the statistical analysis and decided to reject or fail to reject the Null hypothesis, you need to state your conclusion about the claim. To get the correct wording, you need to recall which hypothesis was the claim. If the claim was the null,...

Simple One-sample z-test for the Mean when Sigma is Known

Here is a way to do a simple one-sample z test when we know the population standard deviation sigma. If this was a left tail test as indicated by an < in the alternative hypothesis, the standardized test statistic (z) of -1.753 falls in the rejection region below...

Empirical Rule Cheatsheet

Empirical Rule percentiles are the percentage of data below (to the left of) an x value. Use this Quick and Easy calculator to find percentiles when you are given the population mean and standard deviation and x values. In most intro stats classes, you will only be...

Pick-a-Problem: What difference does it make? 8.1.27

Question: The problem I struggled with this week is 8.1.27. It seemed like all the rest of the problems in the first chapter, but I got it wrong because I used “0” instead of the µ1-µ2 value. Not sure when I am supposed to use that value or how it is determined. I...

Pick-a-Problem: Not given values for µ in 8.1.11

Question: I have hit the wall on a simple problem. I seem to be hitting these more often now. At any rate. 8.1.11, the difference between two means hypothesis test standardized test statistic requires µ1 – µ2. So, how does one calculate this when we are never...