Linear Regressions and Scatterplots

What is the correlation between length of running start and distance of jump?

• positive:  the further you run the further you jump
• negative: the less you run the less distance of your jump
• positive: the further your running start the less your distance

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

• 6
• 50
• 55
• 59

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

Describe the correlation in the graph shown.

• Strong Negative
• Strong Positive
• Weak Negative
• Weak Positive

The linear regression equation for the data is  y = 1.5x + 12.  Interpret the slope of the equation.

• The slope is (0, 1.5).  It means that a pizza with 0 toppings will cost $1.50.
• The slope is 1.5.  It means that it costs $1.50 per topping.
• There are 1.5 toppings.
• There are 1.5 pizzas.

Data was collected on the weight of a male  laboratory rat for the first 25 weeks after its birth. The linear regression equation is 
y= 40x+100, where x is number of weeks and y is weight in grams. 
What does the y-intercept mean in context of the problem?

• The predicted weight of the rat in year 0. 
• The predicted weight of the rat at birth. 
• The current weight of the rat. 
• The average increase in the rat's weight. 

About how many male math teachers were there in 2006?

• 15
• 30
• 35
• 45

Which of the following could be a possible line of best fit for the data?

• y = -5/2x + 20
• y = -x + 19
• y = x + 20
• y = 2/3x + 15 

Estimate the value of r:

• 0.03
• -0.99
• 0.79
• -0.72