Effect Size & Confidence Intervals

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Presentation transcript:

Effect Size & Confidence Intervals Please download the lab files from the course website for Feb. 22

Today’s Objective Review how to generate a z-test using Excel Calculate Effect size and explain what it means Calculate confidence intervals and explain what they mean

Scenario Suppose we would like to know if the number of siblings in Southern families is different than the overall U.S. population. The number of siblings in a typical family in the United States is 0.87 siblings (U.S. Census, 2010) with a standard deviation of 1.38 siblings. We randomly sample 15 students from a statistics class at Auburn University and ask them how many brothers and sisters they have in their immediate family. Use an alpha (probability of a Type I error, p-level) of .01.

Your Turn!!!  We would like to look at the level of satisfaction that people felt when it came to their relationship and compare that to the overall population to see if there is a difference. We use a sample from the statistics students in this class form Auburn University to compare to the overall population. The average level of satisfaction for a typical couple in the United States is 6.06 with a standard deviation of 1.22 (Erol & Orth, 2014). Use an alpha (probability of a Type I error, p-level) of .01.