Transcript PowerPoint for class teaching

What do you see in these scatter plots?
Mean January Air Temperatures
for 30 New Zealand Locations
Temperature (°C)
20
19
18
17
16
15
14
35
40
Latitude (°S)
45
What do you see in these scatter plots?
% of population who are Internet Users vs
GDP per capita for 202 Countries
80
Internet Users
(%)
70
60
50
40
30
20
10
0
0
10
20
30
40
GDP per capita (thousands of dollars)
What do you see in these scatter plots?
Average Age New Zealanders are First Married
30
Age
28
26
24
22
20
1930 1940 1950 1960 1970 1980 1990
Year
What to look for in scatter plots
1. Trend
Linear or non-linear?
What to look for in scatter plots
1. Trend
Positive or negative association?
What to look for in scatter plots
2. Scatter
Strong or weak relationship?
What to look for in scatter plots
2. Scatter
Constant or non-constant scatter?
What to look for in scatter plots
3. Anything unusual
Outlier
What to look for in scatter plots
3. Anything unusual
Groupings
Rank relationships: weakest (1) to strongest (4)
2
4
1
3
Life Expectancy Example
Life Expectancy and Availability of Doctors
for a Sample of 40 Countries
Life Expectancy
80
70
60
50
0
10000
20000
People per Doctor
30000
40000
Life Expectancy Example
Life Expectancy and Availability of Televisions
for a Sample of 40 Countries
Life Expectancy
80
70
60
50
0
100
200
300
400
People per Television
500
600