Satz (Invarianz von Stichprobenvarianz und -standardabweichung)

Sei x n MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamiEaabaaa aaaaaapeGaeyicI4SaeSyhHe6damaaCaaaleqabaWdbiaad6gaaaaa aa@3B47@ eine Stichprobe und v,α n MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaaeaaaaaaaaa8 qacaWG2bGaaiilaiabeg7aHjabgIGiolabl2riH+aadaahaaWcbeqa a8qacaWGUbaaaaaa@3D94@ .

  1. Die Varianz und die Standardabweichung sind translationsinvariant (verschiebungsinvariant), d.h. s x+v 2 = s x 2  und  s x+v = s x , MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaaeaaaaaaaaa8 qacaWGZbWaa0baaSqaaiaadIhacqGHRaWkcaWG2baabaGaaGOmaaaa kiabg2da9iaadohadaqhaaWcbaGaamiEaaqaaiaaikdaaaGccaqGGa GaaeyDaiaab6gacaqGKbGaaeiiaiaadohadaWgaaWcbaGaamiEaiab gUcaRiaadAhaaeqaaOGaeyypa0Jaam4Ca8aadaWgaaWcbaWdbiaadI haa8aabeaakiaacYcaaaa@4AF6@ wobei x+v= ( x i +v ) i MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamiEaiabgU caRiaadAhacqGH9aqpdaqadaqaaiaadIhadaWgaaWcbaaeaaaaaaaa a8qacaWGPbaapaqabaGcpeGaey4kaSIaamODaaWdaiaawIcacaGLPa aadaWgaaWcbaWdbiaadMgaa8aabeaaaaa@40E5@ die um v verschobene Stichprobe bezeichnet.
  2. Die Standardabweichung skaliert linear für nichtnegative Faktoren, d.h. s αx =α s x , MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaam4CamaaBa aaleaaqaaaaaaaaaWdbiabeg7aHjaadIhaa8aabeaakiabg2da9iab eg7aHjaadohadaWgaaWcbaWdbiaadIhaa8aabeaakiaacYcaaaa@3F8E@ für  α0 MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaaeaaaaaaaaa8 qacqaHXoqycqGHLjYScaaIWaaaaa@3A36@ , wobei αx= ( α x i ) i MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeqySdeMaam iEaiabg2da9maabmaabaGaeqySdeMaamiEamaaBaaaleaaqaaaaaaa aaWdbiaadMgaa8aabeaaaOGaayjkaiaawMcaamaaBaaaleaapeGaam yAaaWdaeqaaaaa@404A@ die mit dem Faktor α MathType@MTEF@5@5@+= feaagKart1ev2aqaMPbvLHfij5gC1rhimfMBNvxyNvgaCfgBWHwyam XvP5wqSXMqHnxAJn0BKvguHDwzZbqefqvATv2CG4uz3bIuV1wyUbqe dmvETj2BSbqefm0B1jxALjhiov2DaebbnrfifHhDYfgasaacH8srps 0lbbf9q8WrFfeuY=Hhbbf9v8qqaqFr0xc9pk0xbba9q8WqFfea0=yr 0RYxir=Jbba9q8aq0=yq=He9q8qqQ8frFve9Fve9Ff0dmeaabaqaci GacaGaaeqabaWaaeaaeaaakeaaqaaaaaaaaaWdbiabeg7aHbaa@411D@ skalierte Stichprobe bezeichnet. Für beliebiges reelles α MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaaeaaaaaaaaa8 qacqaHXoqyaaa@37B6@ ist s αx =| α | s x . MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaam4CamaaBa aaleaaqaaaaaaaaaWdbiabeg7aHjaadIhaa8aabeaakiabg2da9maa emaabaGaeqySdegacaGLhWUaayjcSdGaam4CamaaBaaaleaapeGaam iEaaWdaeqaaOGaaiOlaaaa@42B2@