Two students investigated the effect of listening to distracting music on reaction time using the ruler drop test.
Table 1 shows some of their results:
Table 1: Distance the ruler fell before catching (in cm)
| Test | Distance before listening to music (cm) | Distance while listening to distracting music (cm) |
|---|---|---|
| 1 | 12 | 19 |
| 2 | 15 | 22 |
| 3 | 11 | [To be completed] |
| 4 | 14 | [To be completed] |
| 5 | 13 | [To be completed] |
The results for Tests 3, 4, and 5 while listening to distracting music are shown in the diagram below:

Complete Table 1 by finding the values for Tests 3, 4, and 5 while listening to distracting music.
Calculate the mean distance the ruler fell before listening to music and while listening to distracting music.
State the conclusion that can be made from these results and explain how the data supports it.
Suggest two ways the students could improve their investigation.