The whereby property Insurers are liable only for such proportion of the loss that the sum insured bears to the total values at risk.

Termination of an Insurance contract or bond, the premium charge being adjusted in proportion to the time the protection has been in force.
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When the policy is terminated midterm by the insurance company, the earned premium is calculated only for the period coverage was provided. For example: an annual policy with premium of $1,000 is canceled after 40 days of coverage at the company’s election. The earned premium would be calculated as follows: 40/365 days X $1,000=.110 X $1,000=$110.

A clause in an Insurance contract providing that losses will be paid in the proportion that the amount of the contracts bears to the entire amount of Insurance covering the loss.

A clause that requires each insurer covering a risk to share pro rata any losses, in proportion that its particular coverage bears to the total coverage on the risk.

Liability on the part of an Insurer for not more than the proportion of loss which the amount insured bears to the amount of all Insurance policies covering the loss.

The proportion of the original premium or additional premium that the cession bears to the original premium or additional premium that the cession bears to the original line written by the reassured.

A rate charged for a period of coverage shorter than the normal period. An example, if an insured had coverage for only one quarter of a year, his premium would be only one quarter of the annual premium.

Likelihood that a given event will occur. In statistics the relative frequency of occurrence, Probability varies between O (the loss will not occur) and I (the loss will occur).
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The chance that a certain event will occur, represented as a number.
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UK: The science of the measurement of chance. In the theory of probability, certainty is represented by unity. The probability of an event that is not certain is a fraction the smaller the chance of the event happening the smaller the fraction. Insurance, by combining large numbers of similar exposure units, can predict the probability of the insured event with greater accuracy than is possible with small groups or individuals. Mortality tables help actuaries predict with a high degree of accuracy the probabilities of males and females dying at each age by observing a large number of lives. See RISK COMBINATION. –