we can alsoways find the slope by simply using two points off the table, bearing in mind that slope goes by different names
rate of change
average rate of change
delta difference
rise over run
however is the same cat disguised in different costumes.
[tex]\bf \begin{array}{|cc|ll} \cline{1-2} time&distance\\ \cline{1-2} 15&2\\ 30&4\\ 45&5\\ 60&6\\ \cline{1-2} \end{array} \begin{array}{llll} \\[1em] \leftarrow \\\\ \leftarrow \end{array}\qquad \qquad (\stackrel{x_1}{30}~,~\stackrel{y_1}{4})\qquad (\stackrel{x_2}{60}~,~\stackrel{y_2}{6})[/tex]
[tex]\bf \stackrel{\textit{\large average rate of change}}{\stackrel{slope}{m}\implies \cfrac{\stackrel{rise} {\stackrel{y_2}{6}-\stackrel{y1}{4}}}{\underset{run} {\underset{x_2}{60}-\underset{x_1}{30}}}\implies \cfrac{2}{30}\implies \cfrac{1}{15}}[/tex]
