Question

performance.
for the last several tests, kathleen computes the average number of words in each question, x, as well as the average percentage scores on the tests, y.
the correct least squares regression line for the data set is:
$y=-0.488x + 88.253$
use it to complete the following sentence:
if the average question length increased by one word, the least squares regression predicts that the average percentage score would decrease by

Explanation:

Step1: Recall the regression line formula

The regression line is \( y = mx + b \), where \( m \) is the slope and \( b \) is the y - intercept.

Step2: Interpret the slope

In the given regression line \( y=-0.488x + 88.253 \), the slope \( m=-0.488 \). The slope represents the change in \( y \) (average percentage score) for a unit change in \( x \) (average question length).

Answer:

\(0.488\)