In this problem, assume that the distribution of differences is
approximately normal. Note: For degrees of freedom
d.f. not in the Student's t table, use
the closest d.f. that is smaller. In
some situations, this choice of d.f. may increase
the P-value by a small amount and therefore produce a
slightly more "conservative" answer.
In environmental studies, sex ratios are of great importance. Wolf
society, packs, and ecology have been studied extensively at
different locations in the U.S. and foreign...