To identify a table that demonstrates a proportional relationship, we need to check if the ratio \( \frac{y}{x} \) is constant across all pairs in the table.
Let's analyze each table:
-
First table:
x y 2 10 5 20 6 30
Ratios:
- \( \frac{10}{2} = 5 \)
- \( \frac{20}{5} = 4 \)
- \( \frac{30}{6} = 5 \)
Since the ratios are not constant, this table does not show a proportional relationship.
-
Second table:
x y 8 2 12 3 40 4
Ratios:
- \( \frac{2}{8} = 0.25 \)
- \( \frac{3}{12} = 0.25 \)
- \( \frac{4}{40} = 0.1 \)
Since the ratios are not constant, this table does not show a proportional relationship.
-
Third table:
x y 10 2 15 3 40 8
Ratios:
- \( \frac{2}{10} = 0.2 \)
- \( \frac{3}{15} = 0.2 \)
- \( \frac{8}{40} = 0.2 \)
Since all ratios are equal to 0.2, this table shows a proportional relationship.
-
Fourth table:
x y 4 2 9 3 16 4
Ratios:
- \( \frac{2}{4} = 0.5 \)
- \( \frac{3}{9} \approx 0.333 \)
- \( \frac{4}{16} = 0.25 \)
Since the ratios are not constant, this table does not show a proportional relationship.
Conclusion
The third table:
x y
10 2
15 3
40 8
demonstrates a proportional relationship.