Mean, Median, Mode & Range
Find the range of the following numbers:
4, 6, 7, 6, 5, 8, 4
8 - 4 = 4
What does a small standard deviation tell you about a set of data?
The data values are not spread out.
A researcher compares the average stress levels of two groups.
The results show p = 0.12.
Is this result statistically significant at the 0.05 significance level? Explain your answer.
What is "essentially learning that has persisted over time"?
Memory.
Find the mode and range of the following numbers:
12, 15, 18, 12, 20, 15, 25, 12
Mode = 12
Range = 25 - 12 = 13
Two classes both have an average test score of 75.
Which class has the larger standard deviation?
Class B as it has more range in its data set.
A graph compares the average test scores of two classes. The error bars overlap considerably.
Based only on the error bars, would you expect the difference between the classes to be statistically significant? Explain your reasoning.
I would expect statistical insignificance because the error bars are overlapping.
A student learns a list of vocabulary words in their classroom. During the test, they remember the words more easily when they are in the same classroom.
What type of memory cue is this?
Context-dependent cues.
A class sits a memory test and are scored the following marks out of 30:
18, 22, 15, 20, 18, 25, 30, 22, 18, 20
Find the mean.
Two Year 10 maths classes completed the same test.
Distinguish between the two standard deviation scores.
The standard deviation for Class A is 5% which has a smaller dispersion/range than Class B which is 18%.
A psychologist compares anxiety scores before and after a mindfulness program.
The results show:
Draw a conclusion on the effectiveness of this mindfulness program.
The mindfulness program appears to be effective in reducing anxiety levels as the p value and error bars suggest statistical significance.
A psychology researcher wants to investigate context-dependent cues.
One group studies in a quiet library and is tested in the same library. Another group studies in the library but is tested in a noisy classroom.
Which group is likely to perform better on the test?
The group that is tested in the same library.
A psychologist recorded the number of patients they saw each day over a 12-day period:
3, 5, 7, 4, 9, 5, 6, 12, 5, 8, 4, 10
Find the mean and median.
Mean = 6.5
Median = (5 + 6) ÷ 2 = 5.5
Two athletes completed ten 100 m sprints.
Which athlete would a coach consider more reliable and why?
Athlete A because they have a smaller standard deviation.
A researcher investigates whether a new therapy reduces depression scores.
Two graphs are shown:
Which study provides evidence that the therapy was effective and why?
Study A provides stronger evidence because it provided statistically significant results.
A university student studies for an exam at home while listening to music. On the day of the exam, the test is completed in a silent classroom.
Suggest one strategy the student could use to reduce the effect of context-dependent cues during future exams.
The student could study in an environment similar to the exam setting, such as a quiet room without music.
A data set has the following values:
14, 17, 19, 21, 17, 23, 25, 17, 30, 37
Find the mean, median, mode, and range.
Mean = 22
Median = (19 + 21) ÷ 2 = 20
Mode = 17
Range = 37 − 14 = 23
A researcher collects reaction time data from two experiments.
Without performing any calculations:
Which experiment produced more variation and why?
Experiment B because the standard deviation score is larger.
A psychologist tested the effectiveness of three different therapies for reducing stress. Each therapy was compared with a control group.
Therapy A = 0.048
Therapy B = 0.081
Therapy C = 0.001
Rank the therapies from strongest to weakest statistical evidence that they reduced stress.
1. Therapy C
2. Therapy A
3. Therapy B
Describe the role of the hippocampus.
Forms new long-term memories by organising and transferring memories to their permanent storage site.