by Dawn Wright | Feb 28, 2019

Here is a common problem from intro stats: [7.4.30t] A random sample of 100 observations from a population with a standard deviation of 44 yielded a sample mean of 108. Test the null hypothesis that μ = 100 against the alternative that μ > 100 at an alpha of 0.05....
by Dawn Wright | May 18, 2018

This is a great 5-minute read – well worth your time. Spies, Crime, and Lightning Strikes: The Value of Probabilistic Thinking
by Dawn Wright | Apr 25, 2018

Enter your data in the blue cells and the answers will be in the yellow cells.
by Dawn Wright | Apr 16, 2018

by Dawn Wright | Apr 4, 2018

Step 1: Words to Symbols Table Read the problem carefully, looking for key phrases and words which will identify the claim. Look for those key phrases in the table below to determine if the claim is the null or alternative hypotheses. It can be either. Because the...
by Dawn Wright | Mar 31, 2018

Enter your data in the blue cells and the minimum sample size will be in the yellow cell at the bottom. Note: the standard deviation and E must be in the same units (e.g. inches, feet, etc). Download a copy of the workbook Min Sample Size for Mean CI...