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)

Question

Responses

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 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.

Answer 1

To predict the average final grade percentage when a student spent 10 hours on social media using the trend line equation \( y = -7.2x + 98.9 \), we substitute \( x = 10 \) into the equation:

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

Calculating step by step:

1. Calculate \( -7.2 \times 10 = -72 \).
2. Next, add this result to 98.9: \[ y = -72 + 98.9 = 26.9 \]

Rounding 26.9 to the nearest whole number gives us 27.

Therefore, the prediction for the average final grade percentage if a student spent 10 hours on social media is:

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