Mathematics (2019) Grade(s): 8 - Grade 8 Accelerated

MA19.8A.35

Given a scatter plot that suggests a linear association, informally draw a line to fit the data, and assess the model fit by judging the closeness of the data points to the line. [Grade 8, 19]

Unpacked Content

Knowledge

Students know:
  • Patterns found on scatter plots of bivariate data, (e.g., linear/non-linear, positive/negative).
  • Strategies for informally fitting straight lines to bivariate data with a linear relationship.
  • Methods for finding the distance between two points on a coordinate plane and between a point and a line.

Skills

Students are able to:
  • Construct a scatter plot to represent a set of bivariate data.
  • Use mathematical vocabulary to describe and interpret patterns in bivariate data.
  • Use logical reasoning and appropriate strategies to draw a straight line to fit data that suggest a linear association.
  • Use mathematical vocabulary, logical reasoning, and closeness of data points to a line to judge the fit of the line to the data.

Understanding

Students understand that:
  • Using different representations and descriptors of a data set can be useful in seeing important features of the situation being investigated.
  • When visual examination of a scatter plot suggests a linear association in the data, fitting a straight line to the data can aid in interpretation and prediction.

Vocabulary

  • Scatter plot
  • Linear association
  • Quantitative variable
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