Linear regressions and correlation coefficient

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. 

Which scatter plot shows no relationship?

• Graph A
• Graph B
• Graph C
• Graph D

The table shown is comparing a person's foot length to their height in cm. What is the relationship between foot length and height?

• strong; r = .99
• strong; r = .97
• weak; r = .38
• weak; r = .58

what is the formula for linear regression?

• y=mx+b

• a^2+b^2=c^2

• y1~mx1+b

• (1/2)(b)(h)

Estimate the correlation coefficient for this scatterplot.

• A) r = 1.2

• B) r = 0.89

• C)r = 0

• D) r = -0.89

What is a best-fit line 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

Write the equation for the linear regression shown.

• $y=-5.11x+3.23$

• $r=0.8$

• $y=3.23x\ -\ 5.11$ $\$

• $y=0.64x+0.8$

Write the linear regression equation for the following data points. Round to the nearest tenth.

• $y=-0.83x+0.61$

• $y=-0.83x+0.63$

• $y=0.83x+-0.8$

• $a^2+b^2=c^2$

• Positive, strong
• Positive, weak
• Negative, strong
• Negative, weak

• Positive, strong
• Positive, weak
• Negative, strong
• Negative weak