Using Trend Lines Quick Check

Question

4 of 54 of 5 Items

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 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 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.
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.

Answer 1

To predict the average final grade percentage based on the number of hours spent on social media, we can use the given equation of the trend line:

\[ y = -7.2x + 98.9 \]

where \( y \) is the average final grade percentage and \( x \) is the number of hours spent on social media.

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

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

Rounding to the nearest whole number, we get:

\[ y \approx 27 \]

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

So, the correct response is:

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