[tex]\bf \begin{array}{lllll}
round(x)&\boxed{1}&2&3&\boxed{4}\\\\
wrestlers[f(x)]&\boxed{64}&32&18&\boxed{9}
\end{array}
\\\\\\
slope = {{ m}}= \cfrac{rise}{run} \implies
\cfrac{{{ f(x_2)}}-{{ f(x_1)}}}{{{ x_2}}-{{ x_1}}}\impliedby
\begin{array}{llll}
average\ rate\\
of\ change
\end{array}\\\\
-------------------------------\\\\
f(x)= \qquad
\begin{cases}
x_1=1\\
x_2=4
\end{cases}\implies \cfrac{f(4)-f(1)}{4-1}\implies \cfrac{9-64}{4-1}\implies \cfrac{-55}{3}[/tex]
55 over 3, or 55 wrestlers for every 3 rounds, but the wrestlers value is negative, thus 55 "less" wrestlers for every 3 rounds on average.
