To understand the process, if the recipe called for 2 cups of sugar, Katherine could make 6/2 = 3 batches of cookies. If the recipe called for 1/3 cup of sugar, she could make 6 / (1/3 = 6 * (3/1) = (6/1) * (3/1) = 18 batches of cookies. (When dividing by a fraction, "invert and multiply," that is invert the divisor (what you are dividing BY) and change the division to multiplication.

For your problem, 6 / (3/4) = 6 * (4/3) = ____ (for you to finish).