Dr. Aris investigated the effect of high-intensity cognitive training on spatial reasoning under stress. He recorded the number of navigation errors made by five trained fighter pilots during a simulated flight test consisting of 12 critical decision junctions.
The error scores are shown in Table 1.
Calculate the standard deviation for the navigation error scores using the data in Table 1. Show your working and give your answer to two decimal places.
Table 1: Navigation error scores for five trained pilots
| Pilot | Navigation errors (out of 12) |
|---|---|
| P | 2 |
| Q | 4 |
| R | 5 |
| S | 8 |
| T | 11 |
Practise Edexcel A Level Psychology Methods with exam-style questions for A Level Psychology. 638 questions, matched to the Edexcel A Level Psychology (9PS0) specification and written in Paper 1, Paper 2 and Paper 3 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.