Semester One Final Examinations, 2017 AC THE UNIVERSITY OF QUEENSLAND AUSTRALIA This exam paper must not be removed from the venue Venue STAT1201 Analysis of Scientific Data Seat Number Student Number Family Name First Name School of Mathematics & Physics EXAMINATION Semester One Final Examinations, 2017 STAT1201 Analysis of Scientific Data This paper is for St Lucia Campus students. Examination Duration: 120 minutes Reading Time: 10 minutes Exam Conditions: For Examiner Use Only Question Mark This is a Central Examination 1 This is a Closed Book Examination - specified materials permitted 2 During reading time - write only on the rough paper provided 3 This examination paper will be released to the Library 4 Materials Permitted In The Exam Venue: 5 (No electronic aids are permitted e.g. laptops, phones) 6 Calculators - Casio FX82 series or UQ approved (labelled) One A4 sheet of handwritten notes double sided is permitted Materials To Be Supplied To Students: None Total Instructions To Students: This exam has 6 questions, each worth 18 marks. You may attempt at most 5 out of the 6 questions for a maximum of 90 marks. Write your answers in the spaces provided in this examination paper. This paper has 19 pages, including Tables and Formulae Additional exam materials (eg. answer booklets, rough paper) will be provided upon request. Page 1 of 19
Semester One Final Examinations, 2017 STAT1201 Analysis of Scientific Data Question 1 To compare the antioxidant capacities of green and black teas, a researcher bought 43 different brands of tea bags that were widely available in supermarkets across Europe. A random tea baglwaslselectedlfromleachlbrandlandlbrewedlinlalcuplwith1200lmLloflpurifiedlwaterlatl100?I forl20minutes.IAfterl2Iminutes,Ithelantioxidantlcapacityl(inlmilligrams)lofleachlcuplofltealwasl measured. The results are summarised below: sample size sample mean sample standard deviation Black tea 240 239 mg 102 mg Green tea 190 336 mg 139 mg 0 a) Does green tea have higher antioxidant capacity than black tea? Answer this question by carrying out an appropriate hypothesis test. You should clearly statellthelnulllandlalternativelhypotheses,Icomputelalp-value,landIwritelallconclusionlinlal mannerlthanlcanlibelunderstoodlbylalnutritionlresearcher.[[8]marks]] 0 0 n n 0 0 0 0 0 n n b) Statelanylassumption(s)|youlimplicitlylmadelinlansweringlpartl(a)labove.[[2]marks]] 0 0 0 0 Page 2 of 19
STAT1201 Analysis of Scientific Data Semester One Final Examinations, 2017 c) Constructlanlapproximate090%confidencelintervallforltheltruelaverageldifferencelinl antioxidantlcapacitieslbetweenlgreenlandlblacklteas.[[3]marks]] n 0 0 0 n d) Interpretlyourlconfidencelintervallfromlpart!(c)labove.[[1]mark]] 0 e) Suggest two sources of variability that may have contributed to the large range of antioxidantlcapacitieslinlthelteallbags.[[2]marks]I 0 n 0 0 0 f) Suggest two ways to improve the study that addresses the sources of variability you identifiedlinlpartl(e).[[2]marks]] n 0 n Page 3 of 19