\( \definecolor{colordef}{RGB}{249,49,84} \definecolor{colorprop}{RGB}{18,102,241} \)
In this proportional table,
\(\textcolor{colordef}{x}\) \(\textcolor{colordef}{2.5}\) \(\textcolor{colordef}{5}\) \(\textcolor{colordef}{7.5}\)
\(\textcolor{colorprop}{y}\) \(\textcolor{colorprop}{10}\) \(\textcolor{colorprop}{20}\) \(\textcolor{colorprop}{30}\)
calculate the coefficient of proportionality.