They are also classed as summary statistics. The mean (often called the average) is most likely the measure of central tendency that you are most familiar with, ...TaketheTourPlans&PricingSIGNUPMeasuresofCentralTendencyIntroductionAmeasureofcentraltendencyisasinglevaluethatattemptstodescribeasetofdatabyidentifyingthecentralpositionwithinthatsetofdata.Assuch,measuresofcentraltendencyaresometimescalledmeasuresofcentrallocation.Theyarealsoclassedassummarystatistics.Themean(oftencalledtheaverage)ismostlikelythemeasureofcentraltendencythatyouaremostfamiliarwith,butthereareothers,suchasthemedianandthemode.Themean,medianandmodeareallvalidmeasuresofcentraltendency,butunderdifferentconditions,somemeasuresofcentraltendencybecomemoreappropriatetousethanothers.Inthefollowingsections,wewilllookatthemean,modeandmedian,andlearnhowtocalculatethemandunderwhatconditionstheyaremostappropriatetobeused.Mean(Arithmetic)Themean(oraverage)isthemostpopularandwellknownmeasureofcentraltendency.Itcanbeusedwithbothdiscreteandcontinuousdata,althoughitsuseismostoftenwithcontinuousdata(seeourTypesofVariableguidefordatatypes).Themeanisequaltothesumofallthevaluesinthedatasetdividedbythenumberofvaluesinthedataset.So,ifwehave\(n\)valuesinadatasetandtheyhavevalues\(x_1,x_2,\)…\(,x_n\),thesamplemean,usuallydenotedby\(\overline{x}\)(pronounced"xbar"),is:$$\overline{x}={{x_1+x_2+\dots+x_n}\over{n}}$$ThisformulaisusuallywritteninaslightlydifferentmannerusingtheGreekcapitolletter,\(\sum\),pronounced"sigma",whichmeans"sumof...":$$\overline{x}={{\sum{x}}\over{n}}$$Youmayhavenoticedthattheaboveformulareferstothesamplemean.So,whyhavewecalleditasamplemean?Thisisbecause,instatistics,samplesandpopulationshaveverydifferentmeaningsandthesedifferencesareveryimportant,evenif,inthecaseofthemean,theyarecalculatedinthesameway.Toacknowledgethatwearecalculatingthepopulationmeanandnotthesamplemean,weusetheGreeklowercaseletter"mu",denotedas\(\mu\):$$\mu={{\sum{x}}\over{n}}$$Themeanisessentiallyamodelofyourdataset.Itisthevalu