After this lesson, students should be able
analyze data from the real world
apply this data to quadratic functions
use Excel to graph quadratic functions for real-world
The data in the table below represents data
from the lumber industry. The information listed approximates
the number of board feet of lumber per tree in a forest for a
Your tasks are to:
I. Plot the data in Excel.
II. Make conjectures.
III. Given any three points,
write the equation of the graph.
IV. Test your equations using
I. Plotting the data in Excel
A. What is the shape of your graph?
B. What is the direction of opening? (up, down,
C. What is the width of your curve?
D. Is there a minimum point or a maximum point?
II. Making conjectures.
A. Based on Part I, describe the type
of function that would predict the behavior of the graph.
B. Give your best prediction equation based
on what you have learned in the last three sections.
A. What system of equations are you going to
set up to find the equation? (refer to lesson on writing quadratic
B. What is your final equation?
IV. Test your equations by
A. First, graph your best prediction equation
in Part II-B.
How close were you to the actual plotted data?
B. Second, graph the equation obtained in Part
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