Lesson: Estimating Heights

Dear Students,

I am an anthropologist from Canada who investigates changes in human body size and shape over time. I have been working on comparing the differences in heights of people who lived during the 19th century and the present. Unfortunately, I donít always have complete skeletons of the 19th century folks to work from.

Here is where I need your help. I heard through the grapevine that you guys are the best at scientific investigation! Is there a way to predict the height of a person by just knowing the length of the radius bone?
(In case you donít know the radius bone extends from your elbow to your wrist.)

Radius bone

I hope you can help me.


In your group come up with a plan for helping Shelly determine the heights of the people from the measurement of their radius bones.

In your group measure the radius bone and height of each student. (Each group gets a recording sheet like the one below and a measuring device.)

After your group completes their measurements, one person from your group reports your results to the teacher who will record them and then project the cumulative results for the whole class to see.

Describe any patterns that you see.

Plot the ordered pairs.
Draw a line of best fit using a spreadsheet program (or equivalent) like the one below.

Now that you have drawn a line of "best fit" we can use this line to make predictions. For example, if someone had a radius bone that was 17 cm, what would you guess his or her height to be?

Is it possible for someone to have a 17 cm radius bone and have a height of 170 cm? Why?

Having some fun with lines of "best fit"

What if Shaq O'Neil (former Miami Heat basketball player) walked into the room? Could you predict the length of his radius bone? (O'Neil  is 7í 2Ē tall. (Convert his height to centimeters.) How confident are you about your prediction?

In 1951 Eddie Gaedel* batted one time for the St. Louis Brown's baseball team.

Eddie was 3' 7" (110 cm)  tall.  Use the graph that you made to predict the length of Shaq's and Eddie's radius bones.

* More on Eddie Gaedel