4. Each table represents a proportional relationship. For each, find the constant of proportionality, and write an equation that represents the relationship.
$$\text{Unknown environment 'tabular'}$$
$$\text{Unknown environment 'tabular'}$$
Constant of proportionality:
Constant of proportionality:
Equation: $P=$
Equation: $C=$

Step 1 ：The constant of proportionality is the ratio between the two quantities in each table. It can be found by dividing the second quantity by the first quantity.

Step 2 ：For the first table, we can divide $P$ by $s$ to find the constant of proportionality.

Step 3 ：For the second table, we can divide $c$ by $d$ to find the constant of proportionality.

Step 4 ：The equations representing the relationships can be written as $P=k_1\cdot s$ and $C=k_2\cdot d$, where $k_1$ and $k_2$ are the constants of proportionality for the first and second tables respectively.

Step 5 ：The constant of proportionality for the first table is $\boxed{{\displaystyle 4.0}}$ and for the second table is $\boxed{{\displaystyle 3.14}}$.

Step 6 ：The equations representing the relationships are $P=4.0\cdot s$ and $C=3.14\cdot d$.