Answer :
[tex]\begin{gathered} \text{constant of porpotionality =}\frac{y2-y1}{x2-x1} \\ \text{POINT 1 (2,3)} \\ \text{POINT 2 (6},9\text{)} \\ \text{constant of porpotionality =}\frac{9-3}{6-2}=\frac{6}{4}=1.5 \\ \text{constant of porpotionality for this relationship is 1.5,} \\ \text{ it means she n}eeds\text{ 1.5 cups of sugar per each cupcake} \\ \end{gathered}[/tex]