Final answer:
The 4 represents the size of each group, and the unknown is the number of groups.
Step-by-step explanation:
The 4 in this problem represents the size of each group. Since each guest takes home 4 balloons, the 4 represents the number of balloons each guest will receive. To find the number of guests who will have received balloons, divide the total number of balloons (572) by the number of balloons each guest receives (4).
The unknown in this problem is the number of groups. In this case, the number of groups refers to the number of guests who will receive balloons.