To find the constant of proportionality, divide the total amount of basketballs that have been used by the total number of games. This will give you the rate of new basketballs per game:
[tex]\frac{27\text{ basketballs}}{9\text{ games}}=3\text{ basketballs per game}[/tex]Fill the column of "Number of NBA games" with the numbers from 1 to 9. Using the constant of proportionality, multiply each number in the first column by 3 to find how many basketballs are used depending on the number of games.
[tex]\begin{gathered} 1\text{ game }\rightarrow\text{ 3 basketballs} \\ 2\text{ games}\rightarrow6\text{ basketballs} \\ 3\text{ games }\rightarrow9\text{ basketballs} \\ \text{.} \\ \text{.} \\ \text{.} \\ 9\text{ games }\rightarrow27\text{ basketballs} \end{gathered}[/tex]Remember: the proportional relationship being represented is the number of new basketbals that are used per game. The constant of proportionality is 27/9 = 3, and that's the value that belongs next to the 1 in the table.