- HarveyLv 51 decade agoFavorite Answer
The probability that the event will be exceeded during the n-year interval is:
P0 = 1 - (1 - P)^n
Example: For a 10-percent probability of exceedance (P0) over a 50-year (n) interval,
0.1 = 1 - (1 - P)^50 -> P = 0.0021 -> T = 475 years
the annual probability (P) equals 0.0021, corresponding to a return period of 475 yearsSource(s): Ajaya K. Gupta, Peter J. Moss ed. Guidelines for Design of Low-Rise Buildings Subjected to Lateral Forces CRC Press, 1993.