Your teacher surveyed the class to determine the number of hours that each student spent on social media. Your teacher created a table and scatterplot graph that displayed the number of hours and the average final grade based on the hours. The trend line (equation) for the data is y=−7.2x+98.9 . Interpret the slope. How many points does the average final grade decrease for 0 hours on social media?
The slope of the trend line is -7.2. This means that for every additional hour spent on social media, the average final grade decreases by 7.2 points.
To find out how many points the average final grade decreases for 0 hours on social media, we can substitute 0 for x in the equation:
y = -7.2(0) + 98.9
Simplifying the equation:
y = 0 + 98.9
y = 98.9
Therefore, the average final grade does not decrease for 0 hours on social media and remains at 98.9 points.