Edexcel a level statistics question paper 2 june 2023 + mark scheme

Mark Scheme (Results) Summer 2023 Pearson Edexcel GCE In Statistics (9ST0) Paper 02: Statistical InferenceEdexcel and BTEC Qualifications Edexcel and BTEC qualifications are awarded by Pearson, the UK’s largest awar ...

Mark Scheme (Results) Summer 2023 Pearson Edexcel GCE In Statistics (9ST0) Paper 02: Statistical InferenceEdexcel and BTEC Qualifications Edexcel and BTEC qualifications are awarded by Pearson, the UK’s largest awarding body. We provide a wide range of qualifications including academic, vocational, occupational and specific programmes for employers. For further information visit our qualifications websites at www.edexcel.com or www.btec.co.uk. Alternatively, you can get in touch with us using the details on our contact us page at www.edexcel.com/contactus. Pearson: helping people progress, everywhere Pearson aspires to be the world’s leading learning company. Our aim is to help everyone progress in their lives through education. We believe in every kind of learning, for all kinds of people, wherever they are in the world. We’ve been involved in education for over 150 years, and by working across 70 countries, in 100 languages, we have built an international reputation for our commitment to high standards and raising achievement through innovation in education. Find out more about how we can help you and your students at: www.pearson.com/uk Summer 2023 Publications Code 9ST0_02_2306_MS All the material in this publication is copyright © Pearson Education Ltd 2023General Marking Guidance • All candidates must receive the same treatment. Examiners must mark the first candidate in exactly the same way as they mark the last. • Mark schemes should be applied positively. Candidates must be rewarded for what they have shown they can do rather than penalised for omissions. • Examiners should mark according to the mark scheme not according to their perception of where the grade boundaries may lie. • There is no ceiling on achievement. All marks on the mark scheme should be used appropriately. • All the marks on the mark scheme are designed to be awarded. Examiners should always award full marks if deserved, i.e. if the answer matches the mark scheme. Examiners should also be prepared to award zero marks if the candidate’s response is not worthy of credit according to the mark scheme. • Where some judgement is required, mark schemes will provide the principles by which marks will be awarded and exemplification may be limited. • When examiners are in doubt regarding the application of the mark scheme to a candidate’s response, the team leader must be consulted. • Crossed out work should be marked UNLESS the candidate has replaced it with an alternative response.General Marking Guidance Total marks The total number of marks for the paper is 80. Mark types The Edexcel Statistics mark schemes use the following types of marks: • M Method marks, awarded for ‘knowing a method and attempting to apply it’, unless otherwise indicated. • A Accuracy marks can only be awarded if the relevant method (M) marks have been earned. • B Unconditional accuracy marks are independent of M marks • E Explanation marks NOTE: Marks should not be subdivided. Abbreviations These are some of the marking abbreviations that will appear in the mark schemes. • ft follow through • PI possibly implied • cao correct answer only • cso correct solution only (There must be no errors in this part of the question) • awrt answers which round to • awfw answers which fall within (a given range) • SC special case • nms no method shown • oe or equivalent • dep dependent (on a given mark or objective) • dp decimal places • sf significant figures •  The answer is printed on the paperFurther notes • All candidates must receive the same treatment. Examiners must mark the first candidate in exactly the same way as they mark the last. • Mark schemes should be applied positively. Candidates must be rewarded for what they have shown they can do rather than penalised for omissions. • Examiners should mark according to the mark scheme not according to their perception of where the grade boundaries may lie. • There is no ceiling on achievement. All marks on the mark scheme should be used appropriately. • All the marks on the mark scheme are designed to be awarded. Examiners should always award full marks if deserved, i.e. if the answer matches the mark scheme. Examiners should also be prepared to award zero marks if the candidate’s response is not worthy of credit according to the mark scheme. • Where some judgement is required, mark schemes will provide the principles by which marks will be awarded and exemplification may be limited. • When examiners are in doubt regarding the application of the mark scheme to a candidate’s response, the team leader must be consulted. • All A marks are ‘correct answer only’ (cao), unless shown, for example, as A1ft to indicate that previous wrong working is to be followed through. • All M marks are ‘possibly implied’ (PI) unless specifically stated otherwise in the ‘Notes’ column. • After a misread, the subsequent A marks affected are treated as A1ft, but manifestly absurd answers should never be awarded A marks. • Crossed out work should be marked UNLESS the candidate has replaced it with an alternative response. • If two solutions are given, each should be marked, and the resultant mark should be the mean of the two marks, rounded down to the nearest integer if needed.Question Scheme Marks AO Notes 1(a) Wilcoxon Rank Sum M1 2.1a Used or clearly stated or Mann-Whitney (U test) stated H0: 𝜂𝐴 = 𝜂𝐵 H1: 𝜂𝐴 > 𝜂𝐵 B1 1.3 H0: Samples from identical populations H1: Samples from different populations oe Asia (A) Not Asia (B) 1 20 2 19 3 18 5 16 7 14 9 12 16 5 17 4 4 17 6 15 8 13 10 11 11 10 12 9 13 8 14 7 15 6 18 3 19 2 20 1 M1 1.3 Attempt at ranking as one group A1 1.3 All ranking correct Or reversed ranks TA=60 or TB=150 M1dep 1.3 Effort to obtain T (reverse totals 108,102) 𝑈𝐴 = 60 − 1 2 (8)(9) = 24 𝑈𝐵 = 150 − 1 2 (12)(13) = 72 A1 1.3 Either U correctQuestion Scheme Marks AO Notes cv=26 (or 70) B1 1.3 Either cv correct “24” < “26” (or 72>70) Reject H0 M1 2.1b Correct conclusion for their ts and their cv There is significant evidence at the 5% level that players from Asian countries do better than those from non-Asian countries E1dep 2.1a Dep on correct ts & cv 1(b) Possible improvements (not exhaustive) Use a larger sample size Larger than 30 so CLT can be used Ensure sample is randomly selected Select sample from all professional players not just those taking part in the world cup Use more than one video game Use equal sample sizes Use sample from more than one event E1 3.1a Any sensible suggestion 1(c) Numbers of points may not be normally distributed. Positions are discrete rather than continuous. It is not known whether the variances are equal. E1 3.1a Any of theseQuestion Scheme Marks AO