# Sample Size Formula

In Week 1 of RES/342 we determined the optimal sample size, n, using a three variable formula.

Fill in the following table (see attachment) listing the three variables and specify the effect on n (either + or -) of increasing and decreasing each variable, one at a time.

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#### Solution Preview

n = [(z*sigma)/E]^2

z = 1.96, E = 1, sigma changes

sigma = 1 n = 3.8416

sigma = 2 n = 15.3664

sigma = 3 n = 34.5744

sigma = 4 n = ...

#### Solution Summary

The solution provides a step-by-step explanation, filling in the given table, listing the three variables and specifying the effect on n (either + or -) of increasing and decreasing each variable, one at a time.

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