An example of proportion is the number of girls in a class compared to the number of boys.
The statue seems out of proportion.
First measure the proportions of the room.
Have you proportioned the oil in the dressing properly?
The artist proportioned the figure nicely.
A building of large proportions.
To proportion the punishment to the crime.
The proportion of the parts of a building, or of the body.
What is the proportion of helium in the atmosphere?
The proper proportion between oil and vinegar in the dressing.
Origin of proportion
From American Heritage Dictionary of the English Language, 5th Edition