Definition: In relation to drunk driving cases, extrapolation is the process by which a blood alcohol content level at an earlier point in time is estimated, accounting for the driver's age and weight, the amount consumed, the amount of time spent drinking, when the driver stopped drinking and other factors.
Also Known As: Retro-grade extrapolation
Examples: By extrapolation, they estimated his blood alcohol level to be .15 an hour before he took the breathalyzer test.
