Students investigated their reaction times using a computer program that measures reaction time in milliseconds.
Table 1 shows the results of five trials for four students: Student W, Student X, Student Y, and Student Z.
| Test | Student W | Student X | Student Y | Student Z |
|---|---|---|---|---|
| 1 | 280 | 310 | 245 | 342 |
| 2 | 275 | 305 | 255 | 331 |
| 3 | 285 | 820 | 250 | 348 |
| 4 | 290 | 315 | 240 | 336 |
| 5 | 270 | 320 | 260 | 338 |
| Mean | 280 | 312.5 | 250 | M |
State which student and test number represents the anomalous result in Table 1.
Calculate the mean value M for Student Z in Table 1. Show your working.