Answer:
![Constant\ of\ proportionality=(3)/(2)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/dzqlbt3hh996gl2zfq8cegeamo0kclhra7.png)
Explanation:
By definition, Direct proportion equations have the following form:
![y=kx](https://img.qammunity.org/2020/formulas/mathematics/middle-school/ho37lptiefci31wskjnke7d88izbug72ti.png)
Where "k" is the Constant of proportionality.
The graph of a Direct proportional relationship is a straight line that passes through the origin.
In this case you need to pick any point on the line given in the picture. You can choose the following point:
![(4,6)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/nx8ny35dqy6qemm7rapaifp1j05ys2j3ub.png)
So, you can identify that:
![x=4\\y=6](https://img.qammunity.org/2020/formulas/mathematics/middle-school/4nnajmnv9qk2k3qexnfs1s5554qcevupyf.png)
Knowing that, you must substitute these values into the equation
:
![6=k(4)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/ygwondhepn4jfa6a4sb5p35ktxmgp6guua.png)
And finally, you need to solve for "k" in order to find its value. You get that this is:
![(6)/(4)=k\\\\k=(3)/(2)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/3p968m409lesa7furc27tgib1uqb5kv6u8.png)