Week 4 Wednesday | DataDrivenTales

Why It Matters

Data Often Contains Variation

Instead of focusing on one point, we look for the overall pattern to understand what the data suggests.

Positive, negative, or little/no association describes the overall direction.

A regression line models the overall trend and can help us make predictions.

Residual=Actual-Predicted

Guided Examples

Positive association The graph moves upward from left to right.
Strong association The points are close to a line.
Students who studied more hours tended to have higher test scores. Describe what the pattern suggests.
Association does not prove causation. Other factors may also matter.

y=5(4)+60=80 Find the predicted value.
Residual=83-80=3 Use actual minus predicted.
The residual is positive. The actual point lies above the regression line.
The model underestimated the actual value by 3. Interpret the residual in context.

Wednesday Practice

Choose carefully, then use feedback to decide what to try next.

Choose one

Wednesday Reflection

End of Wednesday