Typesetting LaTeX fraction terms to be larger in an equation

Question

I have the following formula in LaTeX, based on Fisher\'s Exact Test. (NOTE: requires the use of the amsmath package for \\binom.)

Answer 1

The following lines define three fraction commands with sizes intermediate between \displaystyle and \textstyle, in order of decreasing size:

\newcommand{\sdfrac}[2]{\mbox{\small$\displaystyle\frac{#1}{#2}$}}
\newcommand{\fdfrac}[2]{\mbox{\footnotesize$\displaystyle\frac{#1}{#2}$}}
\newcommand{\ltfrac}[2]{\mbox{\large$\frac{#1}{#2}$}}

See this page if further explanation is needed.