Answer:
4/9ths of a cup of sugar is needed for one cup of flour.
Step-by-step explanation:
To answer this you need to scale the number of cups of flour up from 3/4 to 1 that ratio would be 4/3 (multiplying a fraction by its own reciprocal will give you 1).
We can then simply take that ratio, and scale the sugar by the same amount:
1/3 * 4/3 = 4/9
