warm up/pod #5 write the sentences. 1. what is the x-coordinate of the point (2, 3)? 2. to plot the...
TRANSCRIPT
Warm Up/POD #5
Write the sentences.
1. What is the x-coordinate of the point (2, 3)?
2. To plot the point (3, 7) you would move right ___
units then up ___ units.
3. To plot the point (4, –5) would you move left or
right first?
2
3 7
right
SCATTER PLOTSLEARN TO DISPLAY AND ANALYZE DATA IN SCATTER PLOTS.
Agenda Warm-Up Notes Vocabulary Words
Vocabulary28. scatter plot29. positive
correlation30. negative
correlation31. no correlation
To find out if two sets of data may be related, you can make a scatter plot of the data values in each set.
A scatter plot has two number lines, called axes—one for each set of data values.
Each point on the scatter plot represents a pair of data values. These points may appear to be scattered or may cluster in the shape of a line or a curve.
Scatter plots Notes
Use the data to make a scatter plot. Describe the relationship between the data sets.
Example 1: Making a Scatter Plot
Type U.S. Only Rest of World
Mammals 63 251
Birds 78 175
Reptiles 14 64
Amphibians 10 8
Fishes 70 11
Clams 61 2
Number of Endangered Species
Step 1: Determine the scale and interval for each axis. Place the number of animals endangered in the U.S. on the horizontal axis and the number of animals endangered in the rest of the world on the vertical axis.
0 20 40 60 80
300 240
180
120 60 0
Example 1 Continued
Type U.S. Only Rest of World
Mammals 63 251
Birds 78 175
Reptiles 14 64
Amphibians 10 8
Fishes 70 11
Clams 61 2
Number of Endangered Species
Step 2: Plot a point for each pair of values.
0 20 40 60 80
300 240
180
120 60 0
Step 3: Label the axes and give the graph a title.
Example 2
Step 1: Determine the scale and interval for each axis. Place the year on the horizontal axis and the number of farm workers on the vertical axis.
1940 1960 1980 2000
10,000
8,000
6,000
4,000
2,000
1940 8,9951950 6,8581960 4,1321970 2,8811980 2,8181990 2,864
Number of farm workers in thousands
Year
Use the data to make a scatter plot. Describe the relationship between the data sets.
Example 2 Continued
Step 2: Plot a point from each pair of values.
1940 8,9951950 6,8581960 4,1321970 2,8811980 2,8181990 2,864
Number of farm workers in thousands
Year
1940 1960 1980 2000
10,000
8,000
6,000
4,000
2,000
Step 3: Label the axes and give the graph a title.
There are three ways to describe data displayed in a scatter plot.
Positive Correlation
The values in both data sets increase at the same time.
Negative Correlation
The values in one data set increase as the values in the other set decrease.
No Correlation
The values in both data sets show no pattern.
Write positive correlation, negative correlation, or no correlation to describe each relationship. Explain.
The number of vacation days is not related to height. So there would not be any correlation between these two variables.
height and number of vacation days
outdoor temperature and coat sales
As the outdoor temperature increases, the number of coat sales will decrease. So there would be a negative correlation between the data sets.
Example 3: Determining Relationships Between Two Sets of Data
There would not be any correlation between these two variables.
eye color and age
Lesson Quiz: Part I
1. Use the data to make a scatter plot. Describe the relationship.
Temperature Attendance
70 100
80 350
75 250
85 400
74 200
82 375
72 260
Beach Attendance
0
100
200
300
400
500
70 75 80 85
Temperature
Att
en
da
nc
e
The graph shows a positive correlation.
Lesson Quiz: Part II
2. Write positive, negative, or no correlation to describe each relationship. Explain
negative correlation; as age increases, attendance decreases.