Scatterplots
A scatterplot shows each individual as a single cross against a vertical axis (for the variable, Y) and a horizontal axis (for the other variable, X).
By convention, we call the variable on the vertical axis Y and the variable on the horizontal axis X.
Metabolic rate of mammals
The table below describes the lifespan and metabolic rate (measured in terms of oxygen consumption per gram of body weight) of various mammals.
Mammal | Lifespan (years) |
Oxygen (cubic cm/g/h) |
---|---|---|
Echidna N American opossum European hedgehog E American mole Little brown bat Owl monkey Squirrel monkey Rhesus monkey Chimpanzee Man Nine-banded armadillo Rabbit Ground squirrel Golden hamster Rat Mouse Guinea pig Gray wolf Red fox Arctic fox Raccoon Cat Asian elephant Horse Goat Sheep Cow |
50.0 5.0 6.0 3.5 20.5 12.0 20.0 29.0 50.0 100.0 6.5 18.0 9.0 3.9 4.7 3.2 7.6 16.2 9.8 14.0 13.7 28.0 69.0 46.0 20.0 20.0 30.0 |
0.22 0.52 0.75 1.90 2.00 0.51 0.83 0.43 0.25 0.22 0.25 0.42 0.87 0.93 0.86 1.49 0.74 0.32 0.52 0.52 0.39 0.44 0.07 0.15 0.19 0.24 0.13 |
This is a bivariate numerical data set, with an additional label variable containing the names of the mammals.
Relationship between lifespan and metabolic rate
A scatterplot of the data is shown below.
Click on any of the crosses to help read that mammal's lifespan and metabolic rate. The general trend for longer-living mammals to have lower metabolic rates is evident from the downward-sloping cloud of points.