Two biology students investigated the effect of performing simultaneous mental arithmetic on reaction times using the ruler drop test.
Table 1 shows some of their results:
Table 1: Distance the ruler fell before catching (in cm)
| Test | Distance caught in silence (cm) | Distance caught while performing mental arithmetic (cm) |
|---|---|---|
| 1 | 14 | 22 |
| 2 | 17 | 25 |
| 3 | 13 | [To be completed] |
| 4 | 16 | [To be completed] |
| 5 | 15 | [To be completed] |
The results for Tests 3, 4, and 5 while performing mental arithmetic are shown in the diagram below:
a.[3]
Complete Table 1 by finding the values for Tests 3, 4, and 5 while performing mental arithmetic.
b.[2]
Calculate the mean distance the ruler fell in silence and the mean distance it fell while performing mental arithmetic.
c.[2]
State the conclusion that can be made from these results and explain how the data supports it.
d.[2]
Suggest two ways the students could improve their investigation.