In this section, you will practice creating a scatterplot, and then using that scatterplot to analyze a relationship that exhibits no 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 from the 2011 National Football League (NFL) season about the number of sacks experienced by different NFL team quarterbacks and the population of the city where the team is located.
   
   

   City	Number of Quarterback Sacks (2011 Season)	Population (thousands, 2011)
   Green Bay	36	104
   New Orleans	24	344
   New England (Boston)	32	625
   Dallas	36	1223
   Detroit	36	707
   Houston	16	2145
   Atlanta	26	432
   San Francisco	44	813
   Pittsburg	40	306
   San Diego	30	1326
   Miami	36	409
   Chicago	23	2707
   Philadelphia	23	1536
   Carolina (Charlotte)	35	751
   Tennessee (Nashville)	19	610
   Arizona (Phoenix)	30	1469
   Baltimore	31	619
   Oakland	17	396
   Cincinnati	24	297
   Seattle	42	621
   Buffalo	22	261
   Denver	10	620
   Kansas City	22	608
   Tampa Bay (Tampa)	29	336
   Cleveland	32	394
   Denver	33	620
   Washington, DC	25	618
   St. Louis	36	319
   Minnesota (Minneapolis)	30	388
   Arizona (Phoenix)	23	1469
   Indianapolis	16	828
   Jacksonville	40	828


Click to see a popup table. From the table in the popup, copy the data from the Number of Quarterback Sacks (2011 Season) column and Population (thousands, 2011)  column. Paste the data into the Data box of the grapher.

Number of Quarterback Sacks (2011 Season)	Population (thousands, 2011)
36	104
24	344
32	625
36	1223
36	707
16	2145
26	432
44	813
40	306
30	1326
36	409
23	2707
23	1536
35	751
19	610
30	1469
31	619
17	396
24	297
42	621
22	261
10	620
22	608
29	336
32	394
33	620
25	618
36	319
30	388
23	1469
16	828
40	828


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

  No. There does not appear to be a detectable pattern in the data. 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 seem to be randomly scattered as you read the graph to the right.

• As the number of sacks increases, what happens to the city’s population?
  
  Interactive popup. Assistance may be required.

  Hint

  The number of sacks is plotted along the horizontal axis, and the population of each city is plotted 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 sacks increases, the city’s population could increase or decrease.

• If a randomly chosen quarterback has a greater number of sacks, what can you predict will be the host city’s population? Interactive popup. Assistance may be required.
  
  

  Hint

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

  Check Your Answer

  If a randomly chosen quarterback has a greater number of sacks, then it is difficult to tell from the graph if the city will have a greater or lesser population.