Since Justin needs
[tex]\frac{4}{5}\text{cups}[/tex]per batch, then he will need
[tex]\frac{4}{5}\times4\text{ cups}[/tex]to make 4 batches.
Therefore, Justin will need:
[tex]\frac{16}{5}\text{cups.}[/tex]Answer:
[tex]\frac{16}{5}\text{cups.}[/tex]