Question

Johnson (1966) measured bills of dusky flycatchers and found that bill lengths of the
males had a mean of 8.15 ± 0.021 mm (mean ± SE) and a coefficient of variation of
4.67 %. On the basis of this information, infer how many specimens must have been
used in the sample.

Answer 1

Coefficient of Variation $=\frac{s} {\bar x} *100$

4.67=$\frac {s} {8.15}*100$

s=0.3806

SE=$\frac {s} {\sqrt n}$

0.021=$\frac {0.3806}{\sqrt n}$

n=$(\frac {0.3806}{0.021})^2$

The sample consists of n=329 speciments.