Scatter Plot Correlation and Line of Best Fit

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

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 pages would be in a book with 19 chapters. 

• 150 pages

• 170 pages

• 190 pages

• 210 pages

Describe the relationship between the variables.

• Strong positive correlation

• Strong negative correlation

• Weak negative correlation

• Weak positive correlation

Describe the correlation in the graph shown.

• Weak Negative

• Weak Positive

• Strong Negative

• Strong Positive

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.

What type of correlation does this graph have?

• positive 

• negative

• none

• all of the above

You are analyzing a scatter plot that has a negative correlation. What is true of the of the x and y values?

• As x increases, y decreases

• As x increases, y increases

• As x decreases, y decreases

Estimate the correlation coefficient.

• r=1

• r=-1

• r=0.5

• r=-0.5