Formula Sheet for Final Exam Mean ! !!! π₯! π₯= π = π₯! + π₯! + π₯! + β― + π₯! π Median:Ifnisodd,middlevalueofsequence;ifniseven,averageof2middlevalues Range=Max–Min Variance s2 = n ( ∑ xi − x i =1 2 ) n −1 Standarddeviation s = s2 IQR=Q3-Q1Outlier:1.5*IQRrule P(A)= !"#$%& !" ! !"#$%& !" !"!#$ c P(A )=1–P(A) P(AorB)=P(A)+P(B)–P(AandB) P(A|B)= P(AandB) P(B) P(AandB)=P(A|B)*P(B)=P(B|A)*P(A) c c P(B)=P(B|A)*P(A)+P(B|A )*P(A ) MutuallyExclusiveEvents:P(AandB)=0 Independentevents:P(A|B)=P(A)P(B|A)=P(B)P(AandB)=P(A)*P(B) Combination πΆ π, π = !! !! !!! ! ππ ! = π(πππ πππ π|π‘ππ π‘ ! ) = ππ’ππππ ππ π‘ππ’π πππ ππ‘ππ£ππ ππ’ππππ ππ π‘ππ’π πππ ππ‘ππ£ππ + ππ’ππππ ππ ππππ π πππ ππ‘ππ£ππ ππ ! = π ππ πππ πππ π π‘ππ π‘ ! = ππ’ππππ ππ π‘ππ’π πππππ‘ππ£ππ ππ’ππππ ππ π‘ππ’π πππππ‘ππ£ππ + ππ’ππππ ππ ππππ π πππππ‘ππ£ππ ππππ ππ‘ππ£ππ‘π¦ = π(π‘ππ π‘ ! |πππ πππ π) = ππ’ππππ ππ π‘ππ’π πππ ππ‘ππ£ππ ππ’ππππ ππ π‘ππ’π πππ ππ‘ππ£ππ + ππ’ππππ ππ ππππ π πππππ‘ππ£ππ ππππππππππ‘π¦ = π π‘ππ π‘ ! ππ πππ πππ π = ππ’ππππ ππ π‘ππ’π πππππ‘ππ£ππ ππ’ππππ ππ π‘ππ’π πππππ‘ππ£ππ + ππ’ππππ ππ ππππ π πππ ππ‘ππ£ππ 1 ππππ£ππππππ = ππ’ππππ ππ ππππππ π€ππ‘β πππ πππ π ππ’πππππ‘ππ¦ πππ‘ππ ππ’ππππ ππ ππππππ ππ π‘βπ π π‘π’ππ¦ ππππ’πππ‘πππ Discreteprobabilitydistribution:µ=ΣxP(x) σ =Σ(x-µ)2P(x) βnβ n! Binomialprobability: p( x) = β β p x q n − x = p x (1 − p)n − x x ! (n − x)! β xβ 2 Forbinomialrandomvariable:µ = np and σ = npq e− µ µ k Poissonprobability:eisapproximately2.71828 P( X = k ) = , k = 0,1,2,... k! ForPoissonrandomvariable:E(X)=Var(X)=µ Themeanandstandarderrorofthesamplingdistributionofasamplemeanare: µx = μ and σx= σ n Formulaforaz-scorewithmeanμandsdσ: X–µ Z= σ The(1–α)*100%confidenceintervalforpopulationmeanisπ₯ ± π§!/! ! ! ConfidenceLevel zα/2 .90 1.645 .95 1.96 .99 2.575 Whenσisunknown,the(1–α)*100%confidenceintervalforpopulationmeanis π π₯ ± π‘!,!"!(!!!) ! π Ztest: One-SidedTest Two-SidedTest H0:µ=µ0 H0:µ=µ0 H1:µ<µ0 H1:µ≠µ0 (orH0:µ=µ0 TestStatistic: H1:µ>µ0) TestStatistic: Rejectionregion: |z|>z (z<-z orz>z ) Rejectionregion: wherez ischosensothat z<–z P(Z>z )=α/2 (orz>z whenH1:µ>µ0) P-value: p=2P(Z>|z|)=2P(Z<-|z|) wherez ischosensothat P(Z>z )=α P-value: p=P(Z<z)(orP(Z>z)whenH1:µ>µ0) α/2 α/2 α α/2 α α α 2 α/2 α/2 Z-testrejectionregion ttest: One-TailedTest H0:µ=µ0 H1:µ<µ0 (orH0:µ=µ0 H1:µ>µ0) TestStatistic: Two-SidedTest H0:µ=µ0 H1:µ≠µ0 TestStatistic: Rejectionregion: |t|>t ,df=n-1(t<-t ,df=n-1,ort>t Wheret ,df=n-1ischosensothat P(T>t ,df=n-1)=α/2 P-value: p=2P(T>|t|)=2P(T<-|t|) Rejectionregion: t<–t ,df=n-1 (ort>t whenH1:µ>µ0) Wheret ,df=n-1ischosensothat P(T>t ,df=n-1)=α P-value: p=P(T<t) (orP(T>t)whenH1:µ>µ0) Proportiontest: One-SidedTest H0:p≥p0 H1:p<p0 (orH0:p≤p0 H1:p>p0) TestStatistic: α/2 α/2 α α/2 α α α Two-SidedTest H0:p=p0 H1:p≠p0 TestStatistic: Rejectionregion: |z|>z (z<-z orz>z ) wherez ischosensothat P(Z>z )=α/2 P-value: p=2P(Z>|z|)=2P(Z<-|z|) Rejectionregion: z<–z (orz>z whenH1:µ>µ0) wherez ischosensothat P(Z>z )=α P-value: p=P(Z<z) (orP(Z>z)whenH1:µ>µ0) α/2 α α/2 α α/2 α α 3 α/2 α/2 α/2 α/2 ,df=n-1) Chi-squaretest: H0:ThereisnoassociationbetweenAandB H1:ThereisassociationbetweenAandB TestStatistic: E = Expected = ,where Rejectionregion: 2 2 χ >χ 1-α(df),df=(r-1)(c-1) P-value: 2 p=P(χ >teststatistic) Twosamplesparametrictests: t-testforindependentsamples: H0:μ1=μ2vs.H1:μ1≠μ2orμ1>μ2orμ1<μ2 TestStatistic: Unequalvariancefortwopopulations: ( x1 − x2 ) − ( µ1 − µ2 ) t= 2 2 s1 s2 + n1 n2 wheredf=approximateddfbySPSSorthesmaller ofn1-1orn2-1. Equalvariancefortwopopulations: (Row Total)(Column Total) Overall Total t-testforpairedsamples: H0:Δ=0vs.H1:Δ≠0orΔ>0orΔ<0, whereΔ=μAfter-μBefore TestStatistic: t= wheredf=n-1 x1 − x2 1 1 sp + n1 n2 whereππ = π! + π! − 2 t= Proportiontestforindependentsamples: H0:p1=p2vs.H1:p1≠p2orp1>p2orp1>p2 TestStatistic: ( pˆ 1 − pˆ 2 ) − 0 z= pˆ 1 (1 − pˆ 1 ) pˆ 2 (1 − pˆ 2 ) + n1 n2 (1 − α ) *100% confidence interval for ( pˆ 1 − pˆ 2 ) is ( pˆ 1 − pˆ 2 ) ± za / 2 pˆ 1 (1 − pˆ 1 ) pˆ 2 (1 − pˆ 2 ) + n1 n2 4 d x After − xBefore = sd sd n ANOVATable: ANOVAFTest: H0:μ1=μ2=μ3=···vs.H1:μ1≠μ2≠μ3≠··· LinearRegression: y=a+b*x,a=Intercept,b=Slopeoftheregressionline. RegressionANOVAFTest: H0:β =0vs.H1:β ≠0 CorrelationTest: H0:ρ=0vs.H1:ρ≠0 Teststatistic: ½ β‘ n−2 β€ t =rβ’ β₯ ≈ t( n − 2 ) β£1 − r 2 β¦ RejectionRegion:|t|>t α/2 ,df=n-2(t<-tα/2,df=n-2,ort>tα/2,df=n-2) RelativeRiskandOddsRatio: Diseased Healthy Exposed a b NotExposed c d π π = π/(π + π) π/π , ππ = π/(π + π) π/π 5