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Data & Modeling

Build confidence with scatterplots, linear models, residuals, correlation, and real-world data decisions.

What you will practice

  • Describe scatterplots as positive association, negative association, or no association.
  • Use lines of best fit to make predictions and interpret slope and y-intercept in context.
  • Use interpolation and extrapolation while judging whether a prediction is reasonable.
  • Calculate and interpret residual = actual - predicted.
  • Use two-way tables and conditional percentages to describe association in categorical data.

Why it matters

Data questions ask students to make sense of real patterns, not just calculate. The goal is to connect graphs, tables, models, and context so predictions feel reasonable and conclusions stay honest.

Student-friendly anchor

A linear model uses y = mx + b. The slope explains the rate of change, the y-intercept explains the starting prediction, and residual = actual - predicted tells how far the model missed for one data point.

What NC Math 1 expects

Based on the Math 1 standards for bivariate data, residuals, linear models, correlation, and causation.

NC.M1.S-ID.6

Represent data on two quantitative variables with scatterplots and describe how the variables are related.

NC.M1.S-ID.6a

Fit a least squares regression line to linear data using technology and use the fitted function to solve problems.

NC.M1.S-ID.6b

Assess the fit of a linear function by analyzing residuals.

NC.M1.S-ID.7

Interpret the rate of change and intercept of a linear model in context, including interpolation and extrapolation.

NC.M1.S-ID.8

Use scatterplots, correlation coefficients, and residual plots to judge the strength, direction, and appropriateness of a linear model.

NC.M1.S-ID.9

Distinguish between association and causation.

Words and ideas to know

These terms support scatterplot, model interpretation, residual, and association questions.

Scatterplot

A graph of paired data values that helps show whether two quantitative variables are related.

Positive Association

A relationship where the points generally rise from left to right.

Negative Association

A relationship where the points generally fall from left to right.

No Association

A relationship where the points do not show a clear upward or downward pattern.

Line of Best Fit

A line that models the overall trend in a scatterplot.

Slope

The rate of change in a linear model. In y = mx + b, the slope is m.

Y-Intercept

The predicted value of y when x = 0. In y = mx + b, the y-intercept is b.

Interpolation

A prediction made inside the range of the observed data.

Extrapolation

A prediction made outside the range of the observed data. These predictions need extra caution.

Residual

The difference between an actual value and a predicted value: residual = actual - predicted.

Two-Way Table

A table that organizes counts for two categorical variables at the same time.

Association

A pattern showing that two variables are related. Association does not automatically prove causation.

How to think through data questions

Start with the story the data tells, then use calculations to support that story.

Read the trend

Positive association rises left to right. Negative association falls left to right. No association has no clear pattern.

Use the model

In y = mx + b, m is the slope and b is the y-intercept. Substitute x-values to make predictions.

Check residuals

Residual = actual - predicted. A positive residual means the actual value was above the prediction.

Compare groups

In two-way tables, compare percentages within the right row or column before making a statement about association.

Choose a Data & Modeling set

Start with DOK 1 fluency, then build toward applications, analysis, and EOC-style mixed practice.