Section A
PS115-4-FY Statistics Test 1
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UNIVERSITY OF ESSEX
1
st
Year Coursework Test 1: January 2022
PS115-4-FY: STATISTICS FOR PSYCHOLOGISTS
Time allowed: 24 hours
Please check on FASER for the deadline to upload your answer.
The times shown on your timetable are in UCT +0 (i.e., Greenwich Mean Time). Please check online
for a conversion to your local time if you will be undertaking your assessment outside the United
Kingdom
Tables and formulae are provided in a separate document. Please download this from Faser.
For determining statistical significance you should use a significance level of .05 unless indicated explicitly
otherwise.
Unless otherwise stated, your final answers should be correct to three significant figures.
Whenever you are asked to give the name of a test or procedure, please give the full name (e.g.,
“independent samples t-test” rather than “t-test”).
Candidates should answer ALL questions.
You must show your workings and the stages you have gone through for all calculations, where
indicated, to get marks. You can find examples of how to show your working on Moodle (see PS115/
General Information/Example of showing your working). Space is available on the answer sheet for
this.
The marks available for each question are shown in square brackets.
About this exam
You have 24 hours to complete this test and you can submit at any time during the 24 hours. This
extended time period gives you the flexibility to work on your exam at a time that suits you.
You are not expected to spend all this time on the exam.
The time allocated for this assessment includes time for you to download this question and
answer paper and to upload your question and answers paper to FASER.
You must submit by the deadline. Please give yourself ample time before the deadline to submit your
exam to avoid any potential problems.
Please allow at least 30 minutes within your exam time to upload your work. Once you have
completed the assessment do not leave it to the last minute to upload.
Please save your work throughout the examination to avoid losing your work.
Please do not communicate with any other candidate in any way during this assessment. Your
response must be your own work. Procedures are in place to detect plagiarism and collusion.
If you need help
Student contacts for all queries, including technical ones
Email Paper queries: Miroslav Sirota,
[email protected] General queries (including FASER questions):
[email protected] IT/technical queries:
[email protected] mailto:
[email protected]mailto:
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[email protected]PS115-4-FY Statistics Test 1
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Write your answers to all question in the spaces provided below.
There are 35 marks available. The marks available for each question are shown in brackets at the end
of the question.
Q1 The frequency distribution below shows the distribution of the number of errors made by 17
participants in a psychology experiment.
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6
5
4
3
2
1
0 0 1 2 3 4 5 6 7 8 9 10 11 12
Number of Errors
TO GET MARKS SHOW YOUR WORKING in the questions Q1ai-Q1aiii.
(a) For the number of errors, state:
(i) the inter-quartile range
[Space for working]
Q1=Size of (17+1)/4 th item=size of 4th item=3
Q3=Size of 3*(17+1)/4 th item=size of 12th item=8
Inter-quartile range=Q3-Q1=8-3=5
Inter-quartile range = 5
(ii) the median
[Space for working]
Median=Size of (17+1)/2 th item=size of 8th item=4
Median = 4
(iii) the mean
[Space for working]
Mean=(3*5+4*3+6*2+7+8+9*2+10+11+12)/17=6.2
Mean =6.2
PS115-4-FY Statistics Test 1
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(b)The distribution of this sample is best described as:
(i)select ONE answer by
bolding or highlighting it:
Positively
skewed
Normally
distributed
Negatively
skewed
Uniform
(ii)select ONE answer by
bolding or highlighting it:
Unimodal Bimodal Multimodal Modern
(c) On the grid below, draw a frequency distribution for a sample of 17 values, with a minimum
value of 1, a single mode of 4, and a median of 5.
To draw the distribution, shade the squares or put X in the squares you want to fill in the
graph below. Each shaded square represents a score.
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6
5
4 X
3
2 X X X
1 X X X X X X X
0 0 1 2 3 4 5 6 7 8 9 10 11 12
Number of Errors
[8 marks]
Q2 Berkowitz and Geen (1967) measured the number of electric shocks given to a confederate by 15
participants in an experiment. They reported the mean number of electric shocks as 5.00.
They then re-analysed their data, omitting the data for the five...