\( \definecolor{colordef}{RGB}{249,49,84} \definecolor{colorprop}{RGB}{18,102,241} \)
In this proportional table,
\(\textcolor{colordef}{x}\) \(\textcolor{colordef}{1}\) \(\textcolor{colordef}{2}\) \(\textcolor{colordef}{3}\)
\(\textcolor{colorprop}{y}\) \(\textcolor{colorprop}{15}\) \(\textcolor{colorprop}{30}\) \(\textcolor{colorprop}{45}\)
calculate the coefficient of proportionality.