Answer:
![s = 7t](https://img.qammunity.org/2021/formulas/mathematics/college/hqek119rgu9b6jbzbgay5vz9nvoh6uhzj4.png)
Explanation:
The table given shows that both variables are directly proportional to each other. That is, as s variable increases, y variable also increases.
Equation to represent this direct proportion would be:
,
where, k = constant of proportionality.
Let's find k from the table given.
Let's use any pair values of of s and t given in the table. Say, s = 21, t = 3
![s = kt](https://img.qammunity.org/2021/formulas/mathematics/college/3m8zfsbavmwc109a7zlf8r0icsci21v6yu.png)
![21 = k3](https://img.qammunity.org/2021/formulas/mathematics/college/3jluteg8gvjfysemkyo4jpiesambb4kwga.png)
Divide both sides by 3
![(21)/(3) = (k3)/(3)](https://img.qammunity.org/2021/formulas/mathematics/college/ydxa7i07rlobdbqcw1q9m7nqtbyuk5t165.png)
![7 = k](https://img.qammunity.org/2021/formulas/mathematics/college/7p2yecfnakybyftgdzhzxq1s905eo76zkr.png)
![k = 7](https://img.qammunity.org/2021/formulas/mathematics/college/ivw5p5gh7s8dyneo5pcmexrcq7m4hq0e1n.png)
Plug in k = 3 into
:
![s = 7t](https://img.qammunity.org/2021/formulas/mathematics/college/hqek119rgu9b6jbzbgay5vz9nvoh6uhzj4.png)