# Isolating T value

The probability R called risk that an exceedance occurs at least once in n successive years.

R = 1 - (1-1/T)^n

T= Return period

EXAMPLE: What return period must a hydrologist use in designing a critical spillway to accept only a 10% risk that flooding will occur in the next 5 years?

0.10 = 1 - (1-1/T)^5

T=48.1 years

HOW? Show me the steps to isolate T

https://brainmass.com/statistics/isolating-value-probability-30245

#### Solution Preview

Hello,

Normally, the best way to isolate a variable where powers are involved is to use logs.

1)0.10 = 1 - (1-1/T)^5

0.10 - 1 = -(1-1/T)^5

-0.9 = -(1-1/T)^5

2)Multiply both sides ...

#### Solution Summary

Detailed help in isolating t-value in a given equation is provided.

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