Relationship Between Two Quantitative Variables

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.

Estimate the correlation coefficient for this scatterplot.

• r = 1.2

• r = 0.89

• r = 0

• r = -0.89

Describe the correlation in the graph shown.

• Strong Negative

• Strong Positive

• Weak Negative

• Weak Positive

The correlation coefficient measures...

• whether there is a relationship between two variables.

• the strength of the relationship between two quantitative variables.

• whether a cause and effect relation exists between two variables.

• the strength of the linear relationship between two quantitative variables.

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

If Joe worked 30 hours, how much is he expected to earn?

• $600

• $200

• $1000

• $800

Which scatter plot shows no relationship?

• Graph A

• Graph B

• Graph C

• Graph D

Which with is the line of best fit?

• Black

• Orange

• Red

• Blue

Make a prediction for a resting heart rate after 6 hours of exercise a week.

• 6

• 50

• 55

• 59

What letter do we use to represent correlation coefficient?

• c

• r

• p

• h