1. Learned Hand Formula: B<PL   Burden of precaution < Probability something will happen * Loss/injury  *This formula helps the jury to think about what the RPP would do.
*Example: U.S. v. Carrol Towing Co. – A barge is destroyed because the tugboat operator was absent at the time of the accident.
2. Foreseeability as a duty determinant
i.What a reasonably prudent person would foresee and do in a given situation.
Ex: leaving a car with the key in the ignition certainly creates a foreseeable likelihood that it will be stolen, which endangers the interests of the owner; also likely that the thief will drive negligently; owner of car would be liable for injuries to the 3rd party; Richards v. Stanley