Unit 10

Scatterplot:

Acronym for describing a scatterplot two variable relationship:

DUFS + context

What does DUFS stand for?

Direction, unusual features, form, strength

Words to describe direction of scatterplot two variable relationship:

Positive, negative, none

Examples of unusual features of scatterplots:

Outliers, clusters

Form of scatterplot two-variable relationships:

Linear or non-linear

What does strength of scatterplot two-variable relationships mean?

How close to the form

Which letter represents variation?

r

What numbers can strength of a correlation take on?

-1 to 1

What can direction of correlation be?

Negative or positive

How to interpret correlation?

The (linear) relationship between x and y is (strength) and (direction)

Is correlation equal to causation?

No

How to calculate residual?

Actual - predicted

How to interpret residual values?

The actual (context) was (residual) above/below the predicted value for x=#

How to interpret slope of regression equations?

For each additional x-context, the predicted y-context increases/decreases by (slope)

How to interpret y-intercept of regression equations?

When x=0 context, the predicted (y-context) is (y-intercept)