Quiz 2: Scatterplots

Which sentence describes the relationship shown on this scatter plot?

• The more time spent training, the longer it takes to run 100 m.  
• As the time spent training increases, the time to run 100 m decreases. 
• As the time spent training decreases, the time to run 100 m decreases. 

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

Which sentence describes the relationship shown on this scatterplot?

• As the temperature decreases, the visitors increase. 
• As the temperature increases, the number of visitors increases. 
• As the visitors increase, the temperature decreases. 
• No correlation

What is a line of best fit 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

What would be the correlation between study time and test grades?

• positive
• negative
• none
• cannot be determined

What type of Correlation?

• Positive Correlation

• Negative Correlation

• No Correlation

Suppose a LINE OF BEST FIT passes through the points (4, 8) and (6, 2). The SLOPE of this line is . . .?

• -3

• -6

• 4

• 2

Suppose data related to the AVERAGE Temperature outside (T) and the number of winter Coats (C) sold at a store is collected and graphed.

The LINE OF BEST FIT has the equation C = -3T + 150.

Use this equation to predict the number of coats sold when the average temperature outside is 20°.

• 40

• 75

• 90

• 115

Suppose data related to the AVERAGE Temperature outside (T) and the number of winter Coats (C) sold at a store is collected and graphed.

The LINE OF BEST FIT has the equation C = -3T + 150.

Use this equation to predict the average temperature outside when the number of coats sold is 45.

• 15

• 35

• 55

• 75

What is the best prediction for the number of candies in the jar when 30 students visit her?

• 90

• 180

• 135

• 150