Answer:
[tex]\frac{16}{21}[/tex] of a dress
Step-by-step explanation:
For illustration
If in 3 hours, I sew 6 clothes
In 1 hour, I would sew (6/3) clothes.
Using the same analogy:
In [tex]\frac{3}{4}[/tex] hours, Lucy sews [tex]\frac{4}{7}[/tex] of a dress.
In 1 hour, Lucy will sew [tex](\frac{4}{7} \div \frac{3}{4})[/tex] dresses
To simplify [tex]\frac{4}{7} \div \frac{3}{4}[/tex] , We change the division sign to multiplication by taking the inverse of  the fraction after the division sign.i.e. [tex]\frac{3}{4}[/tex]
[tex]\frac{4}{7} \div \frac{3}{4}=\frac{4}{7} X \frac{4}{3}=\frac{16}{21}[/tex]
In 1 hour, Lucy sews [tex]\frac{16}{21}[/tex] of a dress.
