1. Scatter Plots
Below is a sample scatter plot, can you tell me what they are designed to show.

2. ANSWER
Scatter plots are similar to line graphs in that each graph uses the horizontal ( x ) axis and vertical ( y ) axis to plot data points.
Scatter plots are most often used to show correlations or relationships among data.

3. Make a scatter plot and interpret them
Common Core #25
Make a scatter plot and interpret them

4. Scatter Plots Type #1
Positive correlations occur when two variables or values move in the same direction.
As the number of hours that you study increases your overall class grade increases

5. Scatter Plots – Positive Correlation
Study Time
Class Grade 55
0.5 61 1 67
1.5 73 2 81
2.5 89 3 91
3.5 93 4 95
4.5 97
Make a prediction for a study time of 5 hours.

6. Negative Correlations occur when variables move in opposite directions
Scatter Plot Type #2
Negative Correlations occur when variables move in opposite directions
As the number of days per month that you exercise increases your actual weight decreases

7. Scatter Plots – Negative Correlation
Work out time
Weight
200
0.5
205 1
190
1.5
195 2
180
2.5 3
170
3.5
177 4
160
4.5 5
150
5.5
168 6
140
6.5 7
130
7.5 8
120
8.5 9
110
9.5
115 10
100
10.5 11 90
11.5 12 80
Make a prediction for 12 days worked out.

8. No correlation exists if there is no noticeable pattern in the data
Scatter Plots #3
No correlation exists if there is no noticeable pattern in the data
There is no relationship between the number of shirts someone owns and their annual salary

9. Scatter Plots – No Correlation
number of shirts owned
salary 1 2 3 50 4 30 5 25 6 17 7 8 40 9 10 11 12 13 19 14 55 15 71 16
Can you make a prediction based on this data?

10. Line of Best Fit
A line of best fit is a line that best represents the data on a scatter plot and often shows a trend in the data.
The line may pass through some of the points, none of the points, or all of the points.
The purpose of the line of best fit is to show the overall trend or pattern in the data and to allow the reader to make predictions about future trends in the data.

11. Lines of Best Fit and Outliers
There is one point on here that would be considered an outlier because it doesn’t go with the data. Which one is it?

12. # of hours of sunshine each day
TWO VARIABLES
# of hours of sunshine each day
# of Visitors to certain part of the beach
What type of relationship would these variables have?

13. Scatter Plot of the Data
I have started a scatter plot for you…finish it.

14. Do you notice a trend? Year 1950 1955 1960 1965 1970 1975 1980 1985
1990
1995
# of Tornadoes
201
593
616
897
654
919
866
684
1133
1234
1200
1000
800
600
400
Do you notice a trend?
200
1950
1955
1960
1965
1970
1975
1980
1985
1990
1995

15. Use the line of best fit to predict how many tornadoes may be reported in the United States in 2015 if the trend continues.
1200
1000
800
600
If the trend continues we predict that there will be 1200 tornadoes reported in 2015.
400
200
1950
1955
1960
1965
1970
1975
1980
1985
1990
1995
2000
2005
2010
2015

16. Practice Problems
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