Student Goal

I can interpret data patterns and choose a reasonable model.

Why It Matters

Math 1 uses models to make predictions and explain relationships in real situations.

Warm-Up

Warm-Up 1

A scatter plot trends upward from left to right. What kind of association is shown?

Warm-Up 2

In y = 12x + 30, what does 12 usually represent in a model?

Short Lesson

Standard Focus

NC.M1.S-ID.6 and NC.M1.S-ID.7: Modeling data with functions

Student-Friendly Standard Goal

I can fit and interpret simple models for data shown in tables or scatter plots.

  • A model is a math representation that describes a pattern.
  • Scatter plots show relationships between two numerical quantities.
  • A line of best fit can summarize a roughly linear pattern.
  • Slope and intercept should be interpreted in the context of the situation.

Guided Examples

Guided Example 1

Interpret a Line of Best Fit

A model for study time and score is s = 6h + 72, where h is hours studied.

Step 1

s = 6h + 72

What does the slope mean?

Guided Example 2

Choose a Reasonable Model

A plant's height is 4, 7, 10, and 13 inches over four equal time intervals.

Step 1

4, 7, 10, 13

What pattern do the heights show?

Practice

Problem 1

A line of best fit has equation y = -3x + 50. What does the negative slope suggest?

Problem 2

Use y = 4x + 9 to predict y when x = 5.

Problem 3

Which association is shown when points trend downward from left to right?

Problem 4

Error analysis: A student says the y-intercept always has to be realistic. What is better thinking?

Problem 5

True or false: Models can be useful even when they are not perfect.

Reflection

How are you feeling about today's skill?

Optional reflection: What is one step, word, or representation from today that you want to remember when Math 1 starts?