Designation:D4460−97(Reapproved2015)StandardPracticeforCalculatingPrecisionLimitsWhereValuesareCalculatedfromOtherTestMethods1ThisstandardisissuedunderthefixeddesignationD4460;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thispracticecoverstechniquesforcalculatingprecisionlimitswhenvaluesarecalculatedfromtwoothermethodshavingprecisionlimits.1.2Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2D1188TestMethodforBulkSpecificGravityandDensityofCompactedBituminousMixturesUsingCoatedSamplesD2041TestMethodforTheoreticalMaximumSpecificGravityandDensityofBituminousPavingMixturesD3203TestMethodforPercentAirVoidsinCompactedDenseandOpenBituminousPavingMixturesE177PracticeforUseoftheTermsPrecisionandBiasinASTMTestMethods3.Definitions3.1Fordefinitionsoftermsusedinthisdocument,consultPracticeE177,orastandarddictionary,orastatisticaltext.3,4,54.SignificanceandUse4.1Precisionlimitsforatestresultthatiscalculatedbyaddition,subtraction,multiplication,ordivisionoftwoothertestresultsthathavevalidprecisionlimitscanbecalculateddirectly.Thissavesthecostanddelayofconductinganinterlaboratorystudy.4.2Attheheartofstatisticaltheoryistheconceptofafrequencydistributionofarandomvariable.Theprecisionlimitoftherandomvariableisdeterminedbythestandarddeviationofthevariable.Thestandarddeviationofarandomvariablethatisthesum,difference,product,orquotientoftwootherrandomvariablescanbecalculatedsimplysolongastheindividualvariablesareindependentandthestandarddevia-tionsaresmallrelativetotheirmeanvalues.TheserestrictionsareusuallymetinASTMmethods.Inthosecaseswhere...
