Massachusetts Comprehensive Assessment System

2018, Grade 8 Mathematics

Question 32: Constructed-Response

Reporting Category: Statistics and Probability
Standard: Mathematics.8.SP.A.03 - Use the equation of a linear model to solve problems in the context of bivariate measurement data, interpreting the slope and intercept. For example, in a linear model for a biology experiment, interpret a slope of 1.5 cm/hr as meaning that an additional hour of sunlight each day is associated with an additional 1.5 cm in mature plant height.
Item Description: Use the equation of a line that models a given context to interpret the slope and intercept, and to solve problems related to the context.

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Scoring Guide and Sample Student Work

Select a score point in the table below to view the sample student response.

Score	Description
4	The student response demonstrates an exemplary understanding of using the equation of a linear model to solve problems in the context of bivariate measurement data, interpreting the slope and intercept.
4
3	The student response demonstrates a good understanding of using the equation of a linear model to solve problems in the context of bivariate measurement data, interpreting the slope and intercept. Although there is significant evidence that the student was able to recognize and apply the concepts involved, some aspect of the response is flawed. As a result the response merits 3 points.
2	The student response demonstrates a fair understanding of using the equation of a linear model to solve problems in the context of bivariate measurement data, interpreting the slope and intercept. While some aspects of the task are completed correctly, others are not. The mixed evidence provided by the student merits 2 points.
1	The student response demonstrates a minimal understanding of using the equation of a linear model to solve problems in the context of bivariate measurement data, interpreting the slope and intercept.
0	The student response contains insufficient evidence of an understanding of using the equation of a linear model to solve problems in the context of bivariate measurement data, interpreting the slope and intercept, to merit any points.

Note: There are 2 sample student responses for Score Point 4.

Grade 8 Mathematics

Question 12: Expressions and Equations

Question 32: Statistics and Probability

Return to the MCAS 2018 Student Work Directory

Last Updated: March 11, 2024