The variable "volume" measures the volume (in liters) of a refridgerator, including the freezer if there is one. The variable "price" is the cost of the refridgerator in dollars.

These observations were collected from the listing of refridgerators for sale on www.shopping.com. The website allows me to browse fridges based on its price, down to increments of $20 - $30. Within each price category, there were anywhere from 10-30 available variety of fridges. Within each category, I just browse and randomly selected the first eligible fridge I see as a sample. This is like a stratified simple random sample. The sample is collected on Feb 25th, 2005

Only compact/mini/ordinary refridgerators and refridgerators/freezers combos were considered eligible for taking a sample from. Commercial refridgerators, commercial freezers, freezers, winecoolers, and countertop built-in compact fridges were not considered part of the population.