ScatterPlots.notebook
September 20, 2009 Integrated Algebra 09/21/09 Mr. Callahan
AIM: How do we create scatter plot graphs?
Do Now: Graph the following points: 1) (6, 4) 2) (5, 1) 3) (2.5, 5)
Integrated Algebra 09/21/09 Mr. Callahan
AIM: How do we create scatter plot graphs?
A Scatter Plot is a graph that relates two groups of data. To make a scatter plot, plot the two groups of data as ordered pairs. Data are usually positive, so most plots are in quadrant I.
Hours
Hours
Watched Test Score Watched
Test Score
0 0 0.5 1 1 1 1.5
92 100 89 82 90 95 85
2 2.5 2.5 3 3.5 4 4.5
80 65 70 68 60 65 55
2
70
5
60
100
Test Score
Let's make a scatter plot of hours of TV watched versus test scores what can you say about the results?
80 60 50
40
20
1
2
3
4
5
Hours Spent Watching Television 1
ScatterPlots.notebook
September 20, 2009 Integrated Algebra 09/21/09 Mr. Callahan
AIM: How do we create scatter plot graphs? Year Daily Newspaper Circulation (millions)
1950 1960 1970 1980 1990 2000 54
59
62
62 62 55
4
46
59
76
Example 1 Households With Television (millions)
92 101
Use the data table above to make a scatter plot of newspaper circulation versus number of televisions in households:
AIM: How do we create scatter plot graphs?
Integrated Algebra 09/21/09 Mr. Callahan
We can use scatter plots to find trends in data. There are three types of relationships sets of data may have:
0
0
Positive Correlation
Negative Correlation Generally, one set of data increases while the other decreases.
Both sets are generally increasing together.
0 No Correlation Sometimes data sets are NOT related.
2
ScatterPlots.notebook
September 20, 2009
AIM: How do we create scatter plot graphs?
Integrated Algebra 09/21/09 Mr. Callahan
0 A Trend Line on a scatter plot shows a correlation more clearly.
3