An agricultural researcher is comparing the yield of two organic fertilisers, 'BioGrow' (Fertiliser A) and 'NutriSoil' (Fertiliser B), on tomato crop yields. Twelve matched pairs of plots were treated, and the weight of tomatoes harvested (in kg) from each plot was recorded in the table below.
| Fertiliser A (BioGrow) | Fertiliser B (NutriSoil) | |
|---|---|---|
| Pair 1 | 24.5 | 21.2 |
| Pair 2 | 18.2 | 18.2 |
| Pair 3 | 30.1 | 32.4 |
| Pair 4 | 15.6 | 19.8 |
| Pair 5 | 22.8 | 20.1 |
| Pair 6 | 27.4 | 27.4 |
| Pair 7 | 19.9 | 23.5 |
| Pair 8 | 31.2 | 28.9 |
| Pair 9 | 25.3 | 26.1 |
| Pair 10 | 17.5 | 17.5 |
| Pair 11 | 29.8 | 26.4 |
| Pair 12 | 21.0 | 24.6 |
Calculate the value of S S\,S in this study. Show your workings.
121 exam-style questions on AQA A Level Psychology Inferential testing (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.