# Accession Number:

## AD0751953

# Title:

## Estimating Limiting Values of the Probability of Rare Events,

# Descriptive Note:

# Corporate Author:

## FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OHIO

# Personal Author(s):

# Report Date:

## 1972-11-10

# Pagination or Media Count:

## 8.0

# Abstract:

Confidence intervals of the probability of the appearance of rare events are estimated as a function of the scale of the sample by which the probability is determined. A table of confidence intervals for actually encountered frequencies at a confidence probability of 99 percent is given. It is noted from the table that true probability of the event and the average period of its recurrence may differ several times from that calculated from the sample of frequency of recurrence. For example, if the probability of some meteorological element, calculated over a 30 year period of observations, is 10 percent average period of recurrence corresponding to ten years, the maximum true value of probability will be equal to 31 percent, and the minimum, to 1.1 percent. Consequently, the minimum possible average period for recurrence will be three years, and the maximum will be 100 years. Author

# Descriptors:

# Subject Categories:

- Meteorology
- Statistics and Probability