Five students, A, B, C, D and E, use five different pH meters to measure the pH of solution X, and obtain the values:
A: 8.16 | B: 8.10 | C: 8.15 | D: 8.09 | E: 8.24 |
The variation in the result is partly due to random variation and partly due to systematic errors in the calibration of each of the pH meters.
The students then measure, without re-calibrating the pH meters, the pH of solution Y, and obtain the values:
A: 8.20 | B: 8.14 | C: 8.15 | D: 8.15 | E: 8.28 |
The aim is to test whether there is a difference in the pH of the two solutions, assuming 95% confidence.
Which ONE of the following analyses is correct?