Mean+Body+Fat

Mean Body Fat Activity
Learning Objective: The student will create a distribution of the sample means. File Name is Male Measurements (Sample Documents | Health). I deleted a few of the attributes. Developed September 2011 // Posted June 2013

Take a look at the data. How many men are in this data set? What is the max and min of the Body Fat attribute? DO NOT FIND THE MEAN YET! What are the units for Body Fat? Select then copy the cases from the case cards and paste into the sampler engine. Set the repeat to 25 and run the sampler. What just happened? Interprete the data that is in the sampler.
 * Step 1 - Examine the Data You Tube Video**
 * Step 2 - Load the sampler You Tube Video**



Would it help to graph the Body Fat attribute? What does the 19.816 represent? What is the sample size? What are the units?
 * Step 3 - Create and interpret a data display You Tube Video Steps 3-5**

Okay, now the fun part. I am going to capture the mean Body Fat percentage (the 19.816) using the history tool. The graph below shows the results of 100 samples with a sample size of 25 men.
 * Step 4 - Collect means from repeated samples**

Interpret the data that is graphed in the history of results of sampler 1 plot. Then, compare the plots. Why is the range of Body Fat percentage about 15 to 25 in the history plot instead of about 10 to 32 (in the plot for the 100th trial)? Why does one plot have 100 elements and the other 25? What is going on here?
 * Step 5 - Analyze the results**

What would happen to the distribution of the means if I decreased or increased the sample size from 25? Make a prediction and then run the simulation to test your conjecture [see Central Limit Theorem for more information].
 * Step 6 - Change the sample size**

** WHOOPS **
I made a huge mistake with regard to the design of this simulation. It is subtle, but does make a difference. I went back and made new screenshots of what I should have done. The mathematics is the same, but there is a change in the random sampling process. What do you think I forgot to do? Is it noticeable? Let me know of you catch another error or if you have any questions. ~kgshafer