Take a look at the original sentence again:
Poor Paola listened to her stomach rumbling loudly,
she would have to wait twenty more minutes before she could dash
to the cafeteria for a quick donut and soda.
You wanted to fix it this way:
Poor Paola listened to her stomach rumbling loudly,
so she would have to wait twenty more minutes before she could dash
to the cafeteria for a quick donut and soda.
Although a comma and a coordinating conjunction like so can legally connect two main clauses, this correction method will not work in the example above. The problem is that so, a coordinating conjunction which shows result, does not join the two main clauses logically. Paola is not waiting to eat because her stomach is rumbling loudly.
You might want to consult the rules for fixing comma splices and fused sentences.
Go back to the sentence to try again.