Question

Trey believes there is a correlation between the number of texts sent during class and GPA. He collected data and found that the line of best fit for his data can be modeled by the equation y = 3.8 − 0.4x.

Identify the slope and the type of association.

The slope is −0.4, which indicates a negative correlation.
The slope is 0.4, which indicates a positive correlation.
The slope is −3.8, which indicates a negative correlation.
The slope is 3.8, which indicates a positive correlation.

Answer 1

The slope of the line of best fit for Trey's data is −0.4, indicating a negative correlation between the number of texts sent during class and GPA.

Step-by-step explanation:

Trey believes there is a correlation between the number of texts sent during class and GPA, and the line of best fit for his data is given by the equation y = 3.8 − 0.4x. In this equation, the slope is −0.4, which represents the average change in the dependent variable (y, GPA) for a one-unit increase in the independent variable (x, number of texts sent during class). Since the slope is negative, it indicates a negative correlation; this means that as the number of texts sent during class increases, the GPA tends to decrease.

Answer 2

A

Step-by-step explanation:

y = 3.8 − 0.4x.

y = − 0.4x + 3.8

so slope = -0.4 negative slope

intercept = 3.8