In this section, you will practice creating a scatterplot, and then using that scatterplot to analyze a relationship that exhibits a positive trend.

Use the ScatterPlot grapher by clicking the image below. The grapher will open in a new tab or window.

Click for additional directions on how to use the grapher.

1. The table below contains data collected twice each month regarding the number of jars of peach preserves sold at a general store in Fredericksburg, Texas, and the number of songs that are downloaded in New York City.
   

   Semi-Monthly Data Collection
   Week	Number of Jars of Peach Preserves Sold in Fredericksburg, Texas	Songs Downloaded in New York City (thousands)
   January 1	8	16
   January 15	15	35
   February 1	17	32
   February 15	11	28
   March 1	19	40
   March 15	25	55
   April 1	30	60
   April 15	31	70
   May 1	33	75
   May 15	37	80
   June 1	35	72
   June 15	32	76
   July 1	28	55
   July 15	15	33
   August 1	22	50
   August 15	24	50
   September 1	28	58
   September 15	17	40
   October 1	16	36
   October 15	8	20
   November 1	13	31
   November 15	17	35
   December 1	11	20
   December 15	15	37

   
   
   Interactive popup. Assistance may be required. Click to see a popup table.

   Number of Jars of Peach Preserves Sold in Fredericksburg, Texas	Songs Downloaded in New York City (thousands)
   8	16
   15	35
   17	32
   11	28
   19	40
   25	55
   30	60
   31	70
   33	75
   37	80
   35	72
   32	76
   28	55
   15	33
   22	50
   24	50
   28	58
   17	40
   16	36
   8	20
   13	31
   17	35
   11	20
   15	37

   
   
   

   From the table in the popup, copy the data from the Number of Jars of Peach Preserves column and Songs Downloaded column. Paste the data into the Data box of the grapher.



2. In the grapher, use the radio buttons to turn on the light grid lines and change the plot type to Scatter.



3. Click the Plot/Update button to generate a scatterplot. Use the scatterplot to answer the questions below.
   
   Interactive popup. Assistance may be required.

   See a sample graph

   

• Do the data points appear to follow a linear trend? How can you tell?
  Interactive popup. Assistance may be required.
  

  Check Your Answer

  Yes. Even though you cannot connect all of the data points with one line, all of the data points lie clustered near a line. Interactive popup. Assistance may be required.

• As you read the graph from left to right, do the points seem to move upward or downward? Interactive popup. Assistance may be required.
  
  

  Check Your Answer

  The points move upward as you read the graph to the right.

• As the number of jars of peach preserves sold in Fredericksburg, Texas increases, what happens to the number of songs downloaded in New York City?
  
  Interactive popup. Assistance may be required.

  Hint

  The number of jars of peach preserves sold is along the horizontal axis, and the number of songs downloaded is along the vertical axis. The values along the horizontal axis increase from left to right, and the values along the vertical axis increase from bottom to top. Interactive popup. Assistance may be required.

  Check Your Answer

  As the number of jars of peach preserves sold in Fredericksburg, Texas, increases, the number of songs downloaded in New York City also increases.

• If a greater number of jars of peach preserves are sold in Fredericksburg, what can you predict will happen to the number of songs downloaded in New York City? Interactive popup. Assistance may be required.
  
  

  Hint

  Use your answer from the previous question to help you. A greater number of jars of peach preserves is indicated by a point farther to the right along the horizontal axis. Interactive popup. Assistance may be required.

  Check Your Answer

  If a greater number of jars of peach preserves is sold in Fredericksburg, Texas, then there should be a greater number of songs downloaded in New York City.
• Do you think that there is a cause-and-effect relationship between the number of jars of peach preserves sold in Fredericksburg, Texas, and the number of songs that is downloaded in New York City? Explain your answer.
  
  Interactive popup. Assistance may be required.

  See a Possible Answer

  No. There may be a correlation between the two events, but it is unlikely that the number of songs downloaded in New York City is caused by the number of jars of peach preserves sold in Fredericksburg, Texas.