Grade:  8^th
Subject:  Math
Topic:  Linear Functions
Submitted by:  M. Beanblossom
March 1, 2008 

Linear Functions
Performance Task

Goal	You will use linear equations to model data, make predictions, and support a position.
Role	You will take on the role of a nutritional expert hired either by the fast food chain or by an anti-fast food advocacy group.
Audience	The target audience will be your peers (teenagers).
Situation	You will work in groups to research nutritional information from fast food restaurants.  You will then analyze the data by creating scatter plots and using linear equations to model the data.
Product	You will work in small groups to write a commercial or persuasive speech.  You will try to convince your audience of teenagers either that fast food can be healthy, or that fast food is terrible and should be avoided.  You will use your graphs and equations to support your chosen position, and you will either record your commercial to be shown in class or perform your speech live during class.
Standard	You must take a position, either pro-fast food or against fast food.  Your commercial or speech must use data from your research, as well as your graph(s) and equation(s) to support your position. See the rubric for details on how your work will be evaluated.

Linear Functions Rubric for Performance Task

Task	Excellent	Proficient	Basic	Below Basic
Researches and reports data about at least two fast food restaurants.	(5) At least two fast food restaurants have been researched.  Data is reported clearly, appropriately, and accurately.	(4) At least two fast food restaurants have been researched.  Data is reported accurately, clearly, in a somewhat appropriate format.	(3) At least two fast food restaurants have been researched.  Data is accurate, but is reported in an unclear or inappropriate format.	(2) Only one fast food restaurant has been researched and/or data is inaccurate and reported in an unclear or inappropriate format.
Makes a scatter plot of the data found for each restaurant.	(5) Data is graphed correctly in scatter plots.  Graphs are labeled clearly, and scales used are appropriate.  The graph is visually appealing (creatively done).	(4) Data is graphed correctly in scatter plots.  Graphs are labeled clearly, and scales used are appropriate.	(3) Data is graphed correctly.  Graphs are not labeled clearly and/or scales used are inappropriate.	(2) Data is graphed incorrectly.
Draws a line of best fit, and writes a linear equation for that line for each scatter plot.	(10) Lines of best fit are drawn appropriately.  Linear equations are written in the correct form (y=mx+b), and both the slope and y-intercept are correct.  Both the slope and y-intercept are explained clearly and correctly in the context of the fast food restaurants.	(8) Lines of best fit are drawn appropriately.  Linear equations are written in the correct form (y=mx+b), and both the slope and y-intercept are correct.	(7) Lines of best fit are drawn appropriately.  Linear equations are written incorrectly (either incorrect form or slope or y-intercept is incorrect).	(5) Lines of best fit are drawn incorrectly.  Linear equations are written incorrectly (incorrect form or slope/y-intercept are incorrect).
Writes and presents a commercial or speech persuading the audience either that fast food is OK to eat, or that they should not eat it at all.	(10) Commercial or speech is creative and persuasive.  A clear position is taken and supported with data and data analysis.	(8) Commercial or speech is persuasive.  A clear position is taken and supported with data and data analysis.	(7) Commercial or speech presents research findings and data analysis, but is not persuasive.  No clear position is taken.	(5) A clear position is taken, but is not supported with data and data analysis.

Grading Scale: 

27-30   A
23-26   B
19-22   C
0-18     F