A student hangs a chain of two paperclips from the South (S\text{S}S) pole of a vertical bar magnet, as shown in the diagram above. The paperclips become magnetised of their own accord by magnetic induction.
State the magnetic polarity (North or South) of:
- The top of the first paperclip (adjacent to the magnet's South pole).
- The bottom of the first paperclip.
- The top of the second paperclip.
- The bottom of the second paperclip.
The student then investigates how the strength of an electromagnet changes with the electrical current running through its coil. The electromagnet's strength is assessed by finding the maximum total mass of paperclips it can support.
The class results for the first four test cases are given in the table below:
| Current (A) | Maximum mass of paperclips held (g) |
|---|---|
| 0.5 | 12 |
| 1.0 | 24 |
| 1.5 | 36 |
| 2.0 | 48 |
When testing a current of 2.5 A, the student obtains the following four repeated measurements:
71,58,62,6071, \quad 58, \quad 62, \quad 6071,58,62,60
Explain how the student should process these four measurements to find the most accurate representative value for 2.5 A.