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Answer:
For every 1 cup of blue paint used, 1.5 cups of red paint are used.
Step-by-step explanation:
1. We know that constant of proportionality is 1.5 because when we divide the number of cups of red paint by the number of cups of blue paint, we get 1.5.
2. Since 1 cup of red paint is used every 1.5 cups of red paint, this is equivalent to the constant of proportionality.
Therefore, the answer is For every 1 cup of blue paint used, 1.5 cups of red paint are used.