Basic Statistical Concepts · You make some observations about the world and then create a theory consisting of a hypothesis and possible alternative hypotheses ...SkiptocontentMenuStatisticsplaysacentralroleinresearchinthesocialsciences,puresciencesandmedicine.Asimplifiedviewofexperimentalresearchisasfollows:YoumakesomeobservationsabouttheworldandthencreateatheoryconsistingofahypothesisandpossiblealternativehypothesesthattrytoexplaintheobservationsyouhavemadeYouthentestyourtheorybyconductingexperiments.Suchexperimentsincludecollectingdata,analyzingtheresultsandcomingtosomeconclusionsabouthowwellyourtheoryholdsupYouiteratethisprocess,observingmoreabouttheworldandimprovingyourtheoryStatisticsalsoplaysacentralroleindecisionmakingforbusinessandgovernment,includingmarketing,strategicplanning,manufacturingandfinance.Statisticsisadisciplinethatisconcernedwiththecollectionandanalysisofdatabasedonaprobabilisticapproach.Theoriesaboutageneralpopulationaretestedonasmallersampleandconclusionsaremadeabouthowwellpropertiesofthesampleextendtothepopulationatlarge.Wenowbrieflydefinesomekeyterms.Thesedefinitionswillbefurtherelaboratedthroughouttherestofthewebsite.Dataanddatasets:observationsfromtheenvironment.Population:acompletesetofdatawhichwewishtostudyoranalyze.Akeyfocusofthefieldofstatisticsisthestudyofcharacteristicsofinterestaboutapopulation.Sample:asubsetofthedatafromthepopulationwhichweanalyzeinordertolearnaboutthepopulation.Amajorobjectiveinthefieldofstatisticsistomakeinferencesaboutapopulationbasedonpropertiesofthesample.Randomsample:asampleinwhicheachmemberofthepopulationhasanequalchanceofbeingincludedandinwhichtheselectionofonememberisindependentfromtheselectionofallothermembers.Randomvariable:avariablethatrepresentsvalue(s)fromarandomsample.Wewilluselettersattheendofthealphabet,especiallyx,yandz,asrandomvariables.Independentrandomvariable:avariablethatischosen,andthenmeasuredormanipulated,bytheresearcherinordertostudysomeobservedbehavior.Dependentrandomvariable:avariable