Question

Rani went around the laboratory where she works and measured her coworkers' ear circumference (in millimeters). Then she matched her results with each coworkers' age and created the following scatterplot and regression line.
The fitted line has a slope of
\[0.48\].
What is the best interpretation of this slope?
Choose 1 answer:
Choose 1 answer:
(Choice A, Checked) On average, each
\[1\] year increase in age was associated with a
\[0.48\] millimeter increase in ear circumference.
A
On average, each
\[1\] year increase in age was associated with a
\[0.48\] millimeter increase in ear circumference.
(Choice B) On average, each
\[1\] millimeter increase in ear circumference was associated with a
\[0.48\] year increase in age.
B
On average, each
\[1\] millimeter increase in ear circumference was associated with a
\[0.48\] year increase in age.
(Choice C) We would predict a person who is
\[0\] years old to have an ear circumference of
\[0.48\,\text{mm}\].
C
We would predict a person who is
\[0\] years old to have an ear circumference of
\[0.48\,\text{mm}\].
(Choice D) We would predict a person who is
\[0\] years old to have an ear circumference of
\[90\,\text{mm}\].
D
We would predict a person who is
\[0\] years old to have an ear circumference of
\[90\,\text{mm}\].

Answer 1

The best interpretation of the slope of the regression line in this context is:

**(Choice A)** On average, each \(1\) year increase in age was associated with a \(0.48\) millimeter increase in ear circumference.

This choice correctly describes the relationship indicated by the slope, which reflects how changes in one variable (age) are associated with changes in another variable (ear circumference).