- Phuong sai cia 2 m6u - S0 quan siit nrvtr nz: l0 vdL 12
-BaclUdo:9vdll
- Ci6 triF (th[c nghiQm) : 1.047619; F = sr2/ s22 - Gia k! P one-tial (P mQt phia ): 0.462995
- Ci6 tri F Critucal one - tail ( Fly thuy6t mot phia): 2.896223
* K6t luat:
C6ch l: Niiu Gi6 triP otre-tial (P m0t phla ) >: a ( mirc y' nghia) thi ch6p nhin Ho
(o12 =oz2 ) nguo. c lei bdc bd Ho ch6p nh{n H1 (o12 + 622 ;.
CAch 2:
- V6i F < l: n6u F >= F Critucal one - tail thl chdp nhan H0 (oL2 =o22 ) ngugc lqi bdc b6
Hs chdp nhan H1 (or2 o o22 ).
-Vdi F>= l: n6u F<:F Critucal one-tail thi ch6p nh0n Ar(or2=o22) ngugc lei bdc b6
Ho chip nh6n Hr (o'12 o o22 ).
yi du ten P oneliat =0.46299 > 0.05 nin chiip nhdn H0: ot2 -i22 :r.
3. So s{nh trung binh
-'-- -
Bat;;;? day Id cin th6ng qua hai inau dii t<i6m ttinh iia rnuy6t Ho : mr = mz (ki
vgng cia bii5n I bnng kj vgng cria bi6n 2) vdi diii thuy6t Hr: mr * mz d mfc ! nghia o .
3.!. So sinh hai miu ttQc lip khi bi6l phuong_sai o 21
.vi o
22
Bditoiin d day h cin th6ng qui hai miu dii ki6m tlinh gia thuy6t Ho : mr = m: (ki
vong crla bi6n I bing k] vgng cria bi6n 2) vdi d6i thuy6t Hr: mr * mz d mrlc f nghia a . Rrit m6u dd hp tu lai t6ng thd phin ph6i ihudn, t.ong $Ot s6 tinh hu5ng nio tt6
chring ta c6 thii usc luqng dugc phuong sai (thuong xiy ra khi diEu tra lqi m$t t6ng thi sau
mQt thdi gian chua l6u, n€n phuong sai chua thay d6i, do tl6 6y phuong sai cria lin di6u tra
trudc ldm o 2r vd o 22 , ching h4n khi xem x€t c6c k6t que phan tich cia hai phdng thi nghiQm
md tl6 chinh xric rl5 6n dinh, iir d6 c6 c6c udc lugng vd phuong sai).
TruUng hqp miu l6n: Khi viec rit hai mlu (uan s6t tir hai t6ng th,6 dugo ti6n hanh mOt
cech d6c lap thi chring ta cO hai mdu dQc l$p. Niiu dung luo. ng cia ci hai miu dEu k1n (thudng quy udc ld n1 > 30, nz > 30) ta c6 th6 tidn hdnh z-test nhung thay hai phuong sai cria tiing th6 o 21 vd o 2 bing phuong sai miu s12 va s22
a. Cdc budc thuc hi6n
CnQ" Orn rOrto Analysis > z-Tesr; Two Sample Jor Mgans, sau.d6 lan lu$ td ldi:
. - Input Variable I Rangi: mi6n vio ctia bi6n I tfc li miln chta s6 lieu, k.i ca tcn ddng
d6u cia mAu quan sit.
- - Inpui Variable 2 Range: MiEn viro cria m5u quan siit thri hai kti c6 t€n ddng tlAu cria
mau quan sat.
- Labels: Nilu cAn th€m ddng diu vA t€n bi6n tht chgn muc niy.