A student investigated the reactivity of metals with hydrochloric acid.
The table below shows the student's results.
| Metal | Temperature increase in ∘C^{\circ}\text{C}∘C (Trial 1) | Temperature increase in ∘C^{\circ}\text{C}∘C (Trial 2) | Temperature increase in ∘C^{\circ}\text{C}∘C (Trial 3) | Temperature increase in ∘C^{\circ}\text{C}∘C (Trial 4) | Mean temperature increase in ∘C^{\circ}\text{C}∘C |
|---|---|---|---|---|---|
| Iron | 12 | 14 | 11 | 15 | 13 |
| Aluminium | 42 | 15 | 46 | 41 | YYY |
| Nickel | 8 | 10 | 7 | 11 | 9 |
Calculate the mean temperature increase YYY for aluminium in the table.
Do not include the anomalous result in your calculation.