An electronic test records the time between a shape appearing on a screen and the student pressing a key. Five students completed the test, practised the same task ten times and then completed the test again.
| Student | L | M | N | P | Q |
|---|---|---|---|---|---|
| Reaction time before practice in s | 0.30 | 0.25 | 0.28 | 0.22 | 0.27 |
| Reaction time after practice in s | 0.24 | 0.23 | 0.25 | 0.20 | 0.22 |
The range is the difference between the longest and shortest reaction times.
Which conclusion is best supported by the data?
After practice, the group had a shorter mean reaction time and a smaller range of reaction times.
After practice, the group had a longer mean reaction time and a smaller range of reaction times.
After practice, the group had a shorter mean reaction time and a larger range of reaction times.
After practice, the group had a longer mean reaction time and a larger range of reaction times.
135 exam-style questions on OCR GCSE Biology 3.1 Coordination and control – the nervous system, covering 3.1.1 Structure of the nervous system, 3.1.2 Coordinated response, 3.1.3 The reflex arc, 3.1.4 Structure of the eye, 3.1.5 Defects of the eye, 3.1.6 Structure and function of the brain, 3.1.7 Difficulties of investigating brain function, and 3.1.8 Limitations in treating nervous system damage. Each one has a worked solution and a mark scheme showing where the marks go.