The following 11 Sample Student Responses represent a range of score points.

Score for Sample Student Response #1: Rubric Score 2

Annotation: This response indicates an incomplete application of a reasonable strategy. The student gives an equation for the line of best fit that is within an acceptable range for the data given. The writer uses alternate variables (x) and (y) but does not define those variables. The graph of the equation is correct. A solution of $182.00 for the cost of an airplane ticket from Baltimore to Orlando, though feasible, is an estimate from the student's own line rather than a calculation using the equation. There is no justification. The response demonstrates a conceptual understanding and analysis of the problem.

Score for Sample Student Response #2: Rubric Score 3

Annotation: This response indicates application of a reasonable strategy that leads to a correct solution in the context of the problem. The student gives an appropriate equation for the line of best fit that is within an acceptable range for the data given. The writer uses alternate variables (x) and (y). The line of best fit is graphed accurately. The student's equation is used to calculate a correct cost of the airplane ticket. The justification for this answer ("I then used Trace and saw that 176.48 really was at 790 miles") is logically sound, fully developed, and supports the solution. Although the student has not redefined the variables from those given in the problem, this response demonstrates a complete understanding and analysis of the problem.

Score for Sample Student Response #3: Rubric Score 2

Annotation: This response indicates an incomplete application of a reasonable strategy that leads to a correct solution in the context of the problem. The representations are essentially correct. The equation is appropriate, but the variables have not been redefined from those given in the problem. The graph of the line of best fit is slightly inaccurate with the y-intercept below the 100.636 given in the student's equation. The student's equation is used to calculate a correct solution of $176.48 for the cost of the airplane ticket. However, there is no justification. This response demonstrates a conceptual understanding and analysis of the problem.

Score for Sample Student Response #4: Rubric Score 1

Annotation: This response indicates little application of a reasonable strategy. The representations are incomplete. The student does not provide an equation for the line of best fit. The student has made a reasonable attempt at graphing a line of best fit. A solution of "about 180 dollars" for a ticket from Baltimore to Orlando is an estimate from the student's own line rather than a calculation using an equation. There is no justification. This response indicates a minimal understanding and analysis of the problem.

Score for Sample Student Response #5: Rubric Score 2

Annotation: This response indicates an incomplete application of a reasonable strategy. The representations are correct; both the equation for a line of best fit and the graph of the equation are within an acceptable range for the data given. The solution for the cost of the airplane ticket represents a correct application of the student's equation; however, an explanation for the solution is provided rather than a justification: "you just plug in 790 for d and you get 179." This response demonstrates a conceptual understanding and analysis of the problem.

Score for Sample Student Response #6: Rubric Score 3

Annotation: This response indicates application of a reasonable strategy that leads to a correct solution in the context of the problem. The student uses a graphing calculator to find an appropriate equation for the line of best fit using alternate variables (x) and (y). The graph of the equation is accurate. The solution for the cost of the airplane ticket, $179.64, represents a correct application of the student's equation. The justification is logically sound and supports the solution: "Using the graph, $179.64 seems more accurate." The student has not redefined the variables from those given in the problem; however, this response demonstrates a complete understanding and analysis of the problem.

Score for Sample Student Response #7: Rubric Score 2

Annotation: This response indicates an incomplete application of a reasonable strategy. The equation is present but is only fundamentally correct, consisting of an algebraic expression that is not set equal to the airfare (f) as required in the problem. The alternate variable (x) is not defined. The graph of the equation is within an acceptable range for the data given. The solution of $177.14 for the cost of an airplane ticket from Baltimore to Orlando represents a correct application of the student's equation; however, an explanation is provided rather than a justification: "…first entering the equation then by pressing 2nd, graph. Then finally I typed in 790 to get my answer." This response demonstrates a conceptual understanding and analysis of the problem.

Score for Sample Student Response #8: Rubric Score 1

Annotation: This response indicates little application of a reasonable strategy. The representations are incomplete. The student has made a reasonable attempt at graphing a line of best fit; however, the slope and the y-intercept are somewhat inaccurate for the data given and are not correctly expressed in the student's attempted equation (d+115f). An estimate of $180.00 for the cost of the airplane ticket is feasible, but the student's equation is not used to arrive at the solution. There is no justification. This response demonstrates a minimal understanding and analysis of the problem.

Score for Sample Student Response #9: Rubric Score 2

Annotation: This response indicates an incomplete application of a reasonable strategy. The representations are essentially correct. The equation is within an acceptable range for the data given, but the graph of the line of best fit is slightly inaccurate; the y-intercept is below the 100 given in the equation. The solution for the cost of the airplane ticket represents a correct application of the student's equation; however, the student provides an explanation for the solution rather than a justification: "I got this by substituting 790 into the equation." This response demonstrates a conceptual understanding and analysis of the problem.

Score for Sample Student Response #10: Rubric Score 3

Annotation: This response indicates application of a reasonable strategy that leads to a correct solution in the context of the problem. The student finds an equation for the line of best fit that is within an acceptable range for the data given. The writer uses the alternate variables (x) and (y). The graph of the equation is correct. The solution of $176.57 for the cost of the airplane ticket represents a correct application of the student's equation. The student's use of the trace function to come up with $176.57 justifies the accuracy of the student's solution: "…by making the same scatter plot and line of best fit and went to 790 on the x-axis." The student has not redefined the variables from those given in the problem; however, this response demonstrates a complete understanding and analysis of the problem.

Score for Sample Student Response #11: Rubric Score 2

Annotation: This response indicates an incomplete application of a reasonable strategy. The representations are incomplete. The student provides an equation that is within an acceptable range for the data given, but does not graph the line of best fit. The solution for the cost of the airplane ticket represents a correct application of the student's equation; however, there is no justification. This response demonstrates a conceptual understanding and analysis of the problem.

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