A group of scientists wants to investigate if they can predict the life expectancy of mammal species given its average heart rate. The table below shows the relationship between average heart rate (in beats per minute) and
life expectancy (in years) for a sample of mammals.
Whale
Elephant
Horse
Lion
Sheep
Pig
Average heart rate (BPM)
20
30
34
50
75
95
Life expectancy (years)
70
70
40
13
15
25
All of the scatter plots below display the data correctly, but which one of them displays the data best?
By convention, a good scatter plot uses a reasonable scale on both axes and puts the explanatory variable on the 2-
axis.