Stats – Lengths of Forearm vs. Foot

Aaron Grow

Math 1040-048

Prof. Trygstad

Term Project – Written Report

 Term Project – Written Report


The purpose of this statistical analysis is to explore the concept that the forearm is close to the same size as the foot in humans.


The study design is supposed to be random sampling.


 Variable 1:  Length of Forearm




Box Plot

Variable 2:  Length of Foot




Box Plot:


Comparing Length of Forearm with Length of Foot

 Linear correlation coefficient:

X-Y Scatter Plot:


The major difficulty that arose while trying to get data from a team mate is the fact that in Pearson, everything is turned into a file that is not accessible via the usual Microsoft Office apparatus.  Everything changes to OpenOffice, which, at the time, I did not have on my computer.  VERY CONFUSING.

Another major difficulty of this project was gathering appropriate data.  I know there was one team mate who would be at a family party with lots of children, which may have skewed the results.  I found much of my data at work, which might balance it out, but would also have a skewing effect, as I practically never see children in my day to day activities.  I really have no idea of one location someone could go that would have a perfectly balanced number of humans gathered.  Family reunions, workplace, the mall, on the sidewalk, the park, all have certain demographic skewing properties.


Though not exactly one-to-one, there is enough correlation to indicate a probable linear relationship between the length of the human forearm and the length of the foot.

 I am quite surprised to see the level of correlation between the length of the forearm and the length of the foot.  While our linear correlation coefficient was not high, like 0.9, it was quite high, at over 0.78.  This shows a clearly linear correlation between the lengths of the forearm and the foot.  Looking at the graph, with a slope of 0.78 and a y-intercept of 2.07 shows this relationship in more “physical terms”.  I would suppose the trendline would have to minimize at about 1.5 inches with a tiny preemie baby.  And I have to mention:  Notice the strange statistic with the forearm length of 5.75 inches and the foot size of 12 inches.  Either this must be an error, or someone with a physical abnormality.


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