Back to Know that straight lines are widely used to model relationships between two quantitative variables — Problem 4 · Task Set 82

Fitting Lines to Data -- Tutor Intake Assessment

This is a quick check on line-fitting concepts: when a line makes sense,
how to judge whether it fits well, and how to use a fitted line to
predict values and write its equation. The goal is to see where to focus
our first sessions together, not to grade you. Work independently,
without notes.

Grade 8·8 problems·~12 min·Common Core Math - Grade 8·container·8-sp-a-2

Work through problems with immediate feedback

Concepts

Line P has a slope of 5 and the data points are widely scattered
around it. Line Q has a slope of 0.5 and the data points cluster
tightly around it. Which line is a better fit for its data?

Line P, because a steeper slope means a stronger relationship

Line Q, because its data points cluster tightly around the line, regardless of slope

Both are equally good fits, since fit quality is not related to scatter

Neither -- fit quality can only be judged with a formula, not by eye