To write and equation we call y=oil and x=vinager, so:
![\begin{gathered} y=k\cdot x \\ \text{Where k is some constant of proportionality} \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/high-school/sww7rb18n79mwlfmcfgf499v4w14pjn2ot.png)
To find the constant k we can use the point in the picture (vinager, oil) = (x, y) = (1, 1.5), so:
![\begin{gathered} x=1,y=1.5 \\ 1.5=k\cdot1\Rightarrow k=1.5 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/high-school/osh1ddmr9ga7so4cy4838rnyr314m2sjba.png)
So, the equation is:
![y=1.5x](https://img.qammunity.org/2023/formulas/mathematics/high-school/qoj7a02tubjqhnl9ebgx2bj4vwse48kn15.png)
Now, the meaning of the point (1, 1.5) is for 1 amount of vinager you need 1.5 amount of oil.