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, x

Question

, and the average final grade percentage, y
, based on the hours. Using the equation of the trend line of the data, y=–7.2x+98.9
, predict the average final grade percentage, to the nearest whole number, if a student spent 10 hours on social media.(1 point)
Responses

The average final grade is 7.2 if a student spent 10 hours on social media.
The average final grade is 7.2 if a student spent 10 hours on social media.

The average final grade is 99% if a student spent 10 hours on social media.
The average final grade is 99% if a student spent 10 hours on social media.

The average final grade is 92% if a student spent 10 hours on social media.
The average final grade is 92% if a student spent 10 hours on social media.

The average final grade is 27% if a student spent 10 hours on social media.

Answer 1

To predict the average final grade percentage based on the equation of the trend line \( y = -7.2x + 98.9 \), where \( x \) is the number of hours spent on social media, we can substitute \( x = 10 \) into the equation:

\[ y = -7.2(10) + 98.9 \]

Calculating this gives:

\[ y = -72 + 98.9 = 26.9 \]

Rounding to the nearest whole number, we find:

\[ y \approx 27 \]

So, the average final grade is approximately 27% if a student spent 10 hours on social media. Therefore, the correct response is:

The average final grade is 27% if a student spent 10 hours on social media.