\begin{equation}
\bar y = \frac{\sum(y_i \times t_i)}{\sum t_i},
\end{equation}
\begin{minipage}[h]{1\textwidth}
\begin{equation}
\overline{K_p} = \sqrt[n]{\prod K_\textup{chain}},
\end{equation}
\begin{tabular}{llll}
where & $\overline{K_p}$ & {---} & coefficient of growth; \\
\addlinespace
& $K_\textup{chain}$ & {---} & \begin{tabular}[t]{@{}l@{}}chain coefficients of growth;\end{tabular} \\
\addlinespace
& $n$ & {---} & \begin{tabular}[t]{@{}l@{}}number of chain coefficients.\end{tabular}
\end{tabular}
\end{minipage}