Question

If the population correlation is expected to be .4, approximately how many subjects are needed to have power equal to .7 (α = .05, two-tailed)?

Answer 1

The statistical power of a study (sometimes called sensitivity) is how likely the study is to distinguish an actual effect from one of chance

In the given scenario-

Power = 0.7

Significance Level = 0.05

Correlation = 0.4

We can do it by using SAS/Online calculators as it cannot be done by hand

Using an online calculator, we can arrive at the following result-

Sample Size = 37.32 = 38

So, the number of subjects needed is 38

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