To make 1 1/2 dozen muffins a recipe uses 3 1/2 cups of flour

how many cups of flour are needed for every dozen muffins made?

3 1/2 divided by 3 = 1.1666

so 1/2 dozen muffins uses 1.1666 cups of flour.

1.1666 x 2 = 2.3332

it takes 2.3332 cups of flour to make a dozen muffins

2.3332 = 2 1/3 cups of flour

2 1/3 cups of flour are needed for every dozen muffins made