Question

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

Answer 1

To find the average final grade percentage \( y \) when a student spends \( x = 10 \) hours on social media, we can substitute \( x \) into the equation of the trend line:

\[
y = -7.2x + 98.9
\]

Substituting \( x = 10 \):

\[
y = -7.2(10) + 98.9
\]
\[
y = -72 + 98.9
\]
\[
y = 26.9
\]

When rounding to the nearest whole number, the average final grade percentage is:

\[
\text{Average final grade} = 27\%
\]

Therefore, the correct response is:

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