Please check the examination details below before entering your candidate information
Candidate surname Other names
Centre Number Candidate Number
Pearson Edexcel
Level 3 GCE
Thursday 20 June 2019
Morning (Time: 2 hours) Paper Reference 9ST0/02
Statistics
Advanced
Paper 2: Statistical Inference
You must have: Total Marks
Statistical Formulae and Tables booklet
Calculator
Candidates may use any calculator permitted by Pearson regulations.
Calculators must not have retrievable mathematical formulae stored in
them.
Instructions
•• Use black ink or ball-point pen.
If pencil is used for diagrams/sketches/graphs it must be dark (HB or B).
Coloured pencils and highlighter pens must not be used.
• centre
Fill in the boxes at the top of this page with your name,
number and candidate number.
• clearly
Answer all questions and ensure that your answers to parts of questions are
labelled.
• Answer the questions in the spaces provided
– there may be more space than you need.
• You should show sufficient working to make your methods clear.
Answers without working may not gain full credit.
• Unless otherwise stated, statistical tests should be carried out at the
5% significance level.
• When a calculator is used, the answer should be given to three significant
figures unless otherwise stated.
Information
•• AThere
booklet ‘Statistical Formulae and Tables’ is provided.
are 7 questions in this question paper. The total mark for this paper is 80.
• – use this asfora guide
The marks each question are shown in brackets
as to how much time to spend on each question.
Advice
•• Read each question carefully before you start to answer it.
Try to answer every question.
•• Check your answers if you have time at the end.
If you change your mind about an answer, cross it out and put your
new answer and any working underneath. Turn over
P61175A
©2019 Pearson Education Ltd.
1/1/1/1/
*P61175A0120*
, Answer ALL questions. Write your answers in the spaces provided.
1 As part of an investigation into marine pollution in a particular area, the mercury content
DO NOT WRITE IN THIS AREA
in the muscles of a sample of 36 dolphins is measured.
These 36 dolphins have muscle mercury content with mean 4.4 μg/g and standard
deviation 2.3 μg/g.
(a) Find a 99% confidence interval for the mean mercury content in the muscles of
dolphins in this area.
(3)
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_____________________________________________________________________________________
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2
*P61175A0220*
, (b) Why is it not necessary to assume that mercury content in dolphin muscle follows a
normal distribution?
(2)
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_____________________________________________________________________________________
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_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________
(c) What assumption is required for the interval calculated in part (a) to be valid?
(1)
_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________
(Total for Question 1 is 6 marks)
DO NOT WRITE IN THIS AREA
DO NOT WRITE IN THIS AREA
3
*P61175A0320* Turn over
Candidate surname Other names
Centre Number Candidate Number
Pearson Edexcel
Level 3 GCE
Thursday 20 June 2019
Morning (Time: 2 hours) Paper Reference 9ST0/02
Statistics
Advanced
Paper 2: Statistical Inference
You must have: Total Marks
Statistical Formulae and Tables booklet
Calculator
Candidates may use any calculator permitted by Pearson regulations.
Calculators must not have retrievable mathematical formulae stored in
them.
Instructions
•• Use black ink or ball-point pen.
If pencil is used for diagrams/sketches/graphs it must be dark (HB or B).
Coloured pencils and highlighter pens must not be used.
• centre
Fill in the boxes at the top of this page with your name,
number and candidate number.
• clearly
Answer all questions and ensure that your answers to parts of questions are
labelled.
• Answer the questions in the spaces provided
– there may be more space than you need.
• You should show sufficient working to make your methods clear.
Answers without working may not gain full credit.
• Unless otherwise stated, statistical tests should be carried out at the
5% significance level.
• When a calculator is used, the answer should be given to three significant
figures unless otherwise stated.
Information
•• AThere
booklet ‘Statistical Formulae and Tables’ is provided.
are 7 questions in this question paper. The total mark for this paper is 80.
• – use this asfora guide
The marks each question are shown in brackets
as to how much time to spend on each question.
Advice
•• Read each question carefully before you start to answer it.
Try to answer every question.
•• Check your answers if you have time at the end.
If you change your mind about an answer, cross it out and put your
new answer and any working underneath. Turn over
P61175A
©2019 Pearson Education Ltd.
1/1/1/1/
*P61175A0120*
, Answer ALL questions. Write your answers in the spaces provided.
1 As part of an investigation into marine pollution in a particular area, the mercury content
DO NOT WRITE IN THIS AREA
in the muscles of a sample of 36 dolphins is measured.
These 36 dolphins have muscle mercury content with mean 4.4 μg/g and standard
deviation 2.3 μg/g.
(a) Find a 99% confidence interval for the mean mercury content in the muscles of
dolphins in this area.
(3)
_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________
DO NOT WRITE IN THIS AREA
_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________
DO NOT WRITE IN THIS AREA
2
*P61175A0220*
, (b) Why is it not necessary to assume that mercury content in dolphin muscle follows a
normal distribution?
(2)
DO NOT WRITE IN THIS AREA
_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________
(c) What assumption is required for the interval calculated in part (a) to be valid?
(1)
_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________
(Total for Question 1 is 6 marks)
DO NOT WRITE IN THIS AREA
DO NOT WRITE IN THIS AREA
3
*P61175A0320* Turn over
