Interpreting Trend Lines Scatterplot

Which of the following would be the most accurate equation for the scatter plot?

• y = -2x - 7

• y = -x + 7

• y = 3x + 7

• y = 25x + 7

What is the slope of this trend line?

• 70

• -3

If m = 8/5 and b = -8/5, what is the equation of the trend line in y= mx + b?

• 0 = 8/5 (1) - 8/5

• y = -8/5 x + 8/5

• y = 8/5 x - 8/5

• y = mx + b

If m = -3/4 and b = 9, what is the equation of the trend line in y= mx + b?

• 0 = -3/4 (9) +9

• y = -3/4 x + 9

• y = -3/4 x - 9

• y = 3/4 + 9

The scatter plot shows the relationship between the number of chapters and the total number of pages for several books.  Use the trend line to predict how many chapters would be in a book with 180 pages. 

• 12 chapters

• 15 chapters

• 18 chapters

• 21 chapters

What type of association does this graph have?

• positive

• negative

• none

• all of the above

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. 

The scatter plot shows the relationship between the number of chapters and the total number of pages for several books. Use the trend line to predict how many chapters would be in a book with 220 pages.

• 22 chapters

• 20 chapters

• 18 chapters

• 26 chapters

What is a line of best fit used for?

• To make predictions

• To make the graph look pretty

• To connect the points

• To make it look like you know what you are doing

Mrs. Collins made a scatterplot to show the relationship between the number of absences and a student’s final exam score. Based on this scatterplot, a student with 6 absences should get approximately what score on the final exam?

• 65

• 92

• 70

• 76