Lesson Plan Title: How tall are you?
by: Bryan Freyberg, NSF Fellow, University of Minnesota Duluth. 2008.
Concept / Topic To Teach: Fitting a line to data (linear regression) and use of scientific
method.
Standards Addressed: MN State Math Standard 7.2.1.2: Understand the concept of
proportionality in real-world and mathematical situations, and distinguish between proportional
and other relationships.
General Goal(s): To increase students’ ability to recognize and quantify linear
relationships through experimentation and plotting data.
Specific Objectives: Students will use inquiry to design and carry out an experiment to
test a hypothesis. Students will plot data in a scatterplot and impose a best-fit line to the
data. Students will formulate an equation for their best-fit line and use the equation to
extrapolate information.
Required Materials: Meter sticks (one stick per pair of students). Student Sheet (1 per
student)
Anticipatory Set (Lead-In): “Have you ever heard people say that your armspan is
supposed to be the same as your height?”
Step-By-Step Procedures:
1. Anticipatory set and brief discussion. Brainstorm with students how to answer the
question through experimentation. (2 minutes)
2. Distribute Student Sheet, pair students, distribute meter sticks. As a class, fill out the
steps to the experiment on the Student Sheet (per anticipatory discussion). (5 minutes)
3. Students take armspan and height measurements in centimeters and compile class
data. (10 minutes)
4. Students produce a scatterplot of the class data on the grid on Student Sheet. (15
minutes)
5. Discuss whether the data supports the hypothesis. Teacher explains linear regression
method and students use a straightedge to fit a line to the data. (5 minutes)
6. Students use their line to answer questions #1 and #2 on the Student Sheet.(5 minutes)
7. To conclude, discuss the validity of this method of linear regression. Teacher
demonstrates the method of least squares and rewards students with the closest prediction
of teacher armspan and Michael Jordan’s armspan. (5 minutes)
8. Extension: Students assign variables to armspan and height and write an equation for
the relationship fitting the class data. Students algebraically verify their answers to
questions 1 and 2 using their equation.
Student Sheet: How tall are you?
Name _______________
Have you ever heard that your armspan is supposed to equal your height?
Let’s design an experiment to find out it that’s true.
Step 1: _________________________________________________
Step 2: _________________________________________________
Step 3: __________________________________________________
Step 4: __________________________________________________
My Hypothesis: _________________________________________________________
Define the variables of your experiment: ____________is the independent variable
and ___________ is the dependent variable.
My height: __________(cm)
My wingspan: __________(cm)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
After the class is finished with the experiment, answer the following questions.
1.) Do the class results for the experiment support your hypothesis?
2.) Measure Mr. Freyberg’s height. Use your graph to predict Mr. Freyberg’s wingspan.
How close were you?
Mr. Freyberg’s height: _________(cm)
My prediction of Mr. F’s wingspan: _________(cm)
Mr. Freyberg’s actual wingspan: _________(cm)
My error in prediction: __________(cm)
*3.) Bonus: Michael Jordan is 6 feet and 6 inches tall. Predict his armspan.