Scatter Plots and Lines of Fit

Tell whether x and y show a positive, a negative, or no correlation.

• Positive correlation

• Negative correlation

• No correlation

Which choice CANNOT be the line of best fit?

The scatter plot shows students' scores for Quiz 1 and Quiz 2. What is the Quiz 1 score for a student who earned a score of 13 on Quiz 2?

• 10

• 19

• 15

• None of the students scored a 13 on Quiz 2.

The scatter plot shows students' scores for Quiz 1 and Quiz 2. One student earned the same score on both Quizzes. What was that score?

• 10

• 19

• 15

• 17

Take a look at the scatter plot and line of best fit at right. Is the line of best fit correct? Why or why not?

• Yes, it falls well within most of the data observed.

• No, most of the data points fall below the line.

• Yes, there are points above and below the line.

• No, the line’s slope does not match the trend of the data.

The scatter plot below shows the number of books read by students in Mrs. Hall’s English class and their final grades. Which statement represents the best description about the line of best fit?

• The more books students read, the lower their English grade.

• The more books students read, the higher their English grade.

• The fewer books students read, the higher their English grade. 

• No relationship exists between the number of books students read and their English grades. 

Take a look at the scatter plot and line of best fit. Is the line of best fit correct? Why or why not?

• No, while the line does cross through some points, it does not follow the slope of the data.

• Yes, there are approximately the same points above and below the line.

• No, not enough points are plotted to determine if this is an accurate line.

• Yes, the line trends closely with the observed data.

TRUE OR FALSE: Data points that lie above the trend line should be about the same distance as data points below the trend line.

• True

• False

TRUE OR FALSE: A line of best fit must go through the origin.

• True

• False

The scatter plot shows students' scores for Quiz 1 and Quiz 2. Find the FALSE statement.

• Two students scored a 20 on Quiz 1

• The lowest score on Quiz 1 was a 10.

• No student scored a 16 on either Quiz.

• One student scored a 20 on Quiz 2.