Slope and Scatterplots

The following scatter plot shows the weights and lengths of some dinosaurs.  Which statement accurately describes the information?

• The information shows a positive correlation.  The weight of a dinosaur tends to increase according to its length.

• The information shows a negative correlation.  the weight of a dinosaur tends to decrease according to its length.

• The information shows no correlation.  The weight and length vary according to the type of dinosaur.

• The information shows no correlation.  The relationship between the weight and length of a dinosaur is uncertain.

For which scatter plot would the line of best fit be represented by the equation y = ½x + 2?

• Graph A

• Graph B

• Graph C

• Graph D

Which data will most likely show a negative correlation when graphed on a scatter plot?

• The outside temperature and the number of people wearing gloves.

• The distance a student lives from school and the amount of time it takes to get to school.

• The number of visitors at an amusement part and the length of the lines for the rides.

• A student's height and grade point average.

This scatter plot shows the average traffic volume and average vehicle speed on a certain freeway for 50 days in 1999.  Which statement best describes this relationship.

• As traffic volume increases, vehicle speed increases.

• As traffic volume increases, vehicle speed decreases.

• As traffic volume increases, vehicle speed increases at first, then decreases.

• As traffic volume increases, vehicle speed decreases at first, then increases.

A researcher gathered data to predict the number of new types of plants (y) that will be in a state park after x years.  After making a scatter plot of the data, she determined the equation of a line of best fit to be
y = 0.25x + 8
Based on the equation, what is the number of new types of plants that will be in the park after 24 years?

• 8

• 14

• 32

• 64

A group of friends recorded the time it took to ride their bikes around the park.  This scatter plot shows their results with the line of best fit.  Which is closest to the number of minutes it would take to complete 9 laps?

• 4

• 5

• 6

• 7

Which equation could describe the line of best fit for this graph?

• y = 5x + 236

• y = -5x + 236

• y = 1/5x + 236

• y = -1/5x + 236

Based on the line of best fit for the scatter plot, which of the following amounts is closest to the cost of a 120-minute phone call?

• $10

• $12

• $15

• $20

Which graph shows the line of best fit?

• Graph A

• Graph B

• Graph C

• Graph D

Which scatterplot suggests a linear relationship between x and y?

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