Thirty balloons were selected at random from a box of 60 balloons and filled with helium. The other 30 balloons were filled with regular air. The circumference of each balloon was measured immediately after being filled and then again three days later. Based on the data, which of the following questions could be answered?

1.Are helium-filled balloons more popular than air-filled balloons are?

2.Do helium-filled balloons float higher after three days than air-filled balloons do?

3.Do helium-filled balloons shrink more in three days than air-filled balloons do?

4.Is it easier to fill balloons with helium than to fill them with air?