And Answers
Datagcangbegcollectedgvia?g-gCORRECTggANSWER-Observationsg
Interviewsg
Questionnaires
Experimentsg
Tests
Example:gAgpairgofgjeansgisgpricedgatg£59.50gaftergag30%greduction,gwhatgwasgthegoriginalg
price?g-gCORRECTggANSWER-100%-30%g=g70%g
Newgpriceg(70%)g=g£59.50g
Originalgpriceg=g59.50/70gxg100
Givegangexamplegofgthegdependentg(responsive)gvariable?g-gCORRECTggANSWER-
Thegnumbergofgicegcreamsgsold
Givegangexamplegofgthegindependentg(explanatory)gvariable?g-gCORRECTggANSWER-
Thegtemperature
Howgdogyougfindgagpercentagegofgagquantity?g-gCORRECTggANSWER-
Decimalgxgquantityge.g.g0.35gxg175
Howgdogyougfindgonegquantitygasgagpercentagegofganotherg-gCORRECTggANSWER-
Dividegthegquantitygbygthegothergquantityge.gg200/800gxg100
Howgdogyougfindgthegoriginalgvalueg(percentages)g?g-gCORRECTggANSWER-
Examples:gValuegofgangapartmentgincreasesgbyg12%gtog£125,000g
Newgpriceg=g112%g
Originalgpriceg=g125000/112gxg100
Howgtogcomparegtwogquantitiesg(percentages)?g-gCORRECTggANSWER-
Example:gAgsalarygofg£22,000gisgincreasedgbyg£660gandgagsalarygofg£48000gisgincreasedgb
yg£1000,gwhichgisgthegbiggestgincrease?g
660/22000gxg100g
1000/48000gxg100
Howgtogincreasegpercentages?g-gCORRECTggANSWER-Example:g
, 150gxg1.15g(increasegbyg15%)
Whatgaregthegadvantagesgofgclustergsampling?g-gCORRECTggANSWER-
Cheaperg+gablegtogshowgregionalgvariations
Whatgaregthegadvantagesgofgcumulativegfrequencyggraphs?g-gCORRECTggANSWER-
Usefulgitgsourcegofgdatagisgunsure/lost.gCanggivegestimatesgofgmediangandgquartiles
Whatgaregthegadvantagesgofghistograms?g-gCORRECTggANSWER-
Givesgproportionalgrepresentationgofgeachgclassgintervalgwithingdistribution.gMediangandgq
uartilesgcangbegestimated
Whatgaregthegadvantagesgofgquotagsampling?g-gCORRECTggANSWER-
Easygtogcapturegforgmostgsections
Whatgaregthegadvantagesgofgrandomgsampling?g-gCORRECTggANSWER-Nogbias
Whatgaregthegadvantagesgofgstem-and-leafgdiagrams?g-gCORRECTggANSWER-
Goodgforgsmallgdatagsets,gusefulgforgfindinggmedian.gBack-to-backgcangcomparegtwogsets
Whatgaregthegadvantagesgofgstratifiedgsampling?g-gCORRECTggANSWER-
Proportionallygrepresentativeg-gcanghighlightgtrendsgingeachglayer
Whatgaregthegadvantagesgofgthegmedian?g-gCORRECTggANSWER-
Notgaffectedgbygextremegvalues
Whatgaregthegadvantagesgofgthegrange?g-gCORRECTggANSWER-
Givesgtheglargestgspreadgofgdata
Whatgaregthegadvantagesgofgusinggboxgandgwhiskergplots?g-gCORRECTggANSWER-
Showsgrange,gIQR,gmediag+gextentgofgskew.gUsefulgforgcomparing.
WhatgaregthegadvantagesgofgusinggthegIQR?g-gCORRECTggANSWER-
Givesgthegspreadgforgthegmiddleg50%gofgdatagsogreducesgthegeffectgofgextremes
Whatgaregthegadvantagesgofgusinggthegmean?g-gCORRECTggANSWER-
Allgdatagitemsgaregused
Whatgaregthegadvantagesgofgusinggthegmode?g-gCORRECTggANSWER-
Goodgforgqualitativegdata,gnogcalculationsgneeded
Whatgaregthegadvantagesgofgusinggthegupper/lowergquartiles?g-gCORRECTggANSWER-
Notgaffectedgbygextremegvalues
Whatgaregthegconditionsgofgclustergsampling?g-gCORRECTggANSWER-
Distinctiveggroups/typesgwithingagpopulation