PSY 371 Homework 9 PDF

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This document includes mandatory assignment questions&answers for PSY 371 class in fall 2016....

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Minjeong Kim Dr Ben-zeev PSY 371 16 November 2016

A.Wh a ta r et hen ul la n da l t e r n a t i v eh yp o t he s e st obet e s t e d? H 0 : μ1 - μ 2 = 0

H a : μ1 - μ2 ≠ 0 B. Wha ti st hec r i t i c a lv a l ueo ft het e s ts t a t i s t i c ?( a s s u mea l ph a=. 05 ) 1 ) +( n2 1 )=( 71) +( 7 1)=12 d f =( n1 When α= .05 and degree of freedom is 12, using df=12. Thus,

T crit is ±2.179 in the given t-table with

T crit = ±2.179

C. Wh a ti st h ec o mp u t e d / o bt a i n e dv a l u eoft het e s ts t a t i s t i c ? 2

=

Sp

( n1−1 ) s 12 +( n2−1 ) s22 ( 7−1 ) 1.272 + ( 7− 1 ) 1.072 9.6744 + 6.8694 = = = 12 ( ) ( ) n −1 + n −1 7−1 + 7 − 1 ( 1 ) ( 2 )

1 . 3 786 5 S x

1

−x 2

T obt

=

√

2

Sp (

1 1 + ) = n1 n2

√

1 1 1.37865( + ) 7 7

=

μ ( 2.57 −1.86 )−0 (¿ ¿ 1−μ2) = ( ´x 1−´x 2) − = 0.6276 S x −x ¿ 1

2

6 27 6 √0.3939 =0.

=

0.71 0.6276

=1. 13 13=+1 . 1 3

D.Wh a ti sy o urc o nc l u s i o na bo utt henu l lh yp o t he s i s( r e j e c to rno t ) ?

sno tf a l li nr e gi o nso fr e j e c t i on. Th us , If a i l e d T obt doe t or e j e c tt hen ul lh ypo t he s i s .

−T crit

μ

E. Wha ti sy ou rs ub s t a nt i v ec on c l us i o n? The r ei sn os t a t i s t i c a l l ys uffic i e nte vi d e n c et os u ppo r tt h a tc h i l dr e nwh owa t c he dv i ol e n t TVha v ehi g he rnu mb e rofa g gr e s s i v ea c t i o n, t ( 12 )=1 . 13 ,p >. 05 .

F. Pr o v i det hec on fide nc ei nt e r v a lf o rt h edi ffe r e n c eb e t we e nt hep opu l a t i onme a ns S x

1

−x 2

( - T crit )+( ´x 1−´x 2 ¿ ≤ μ1− μ2 μ1 − μ2

0 . 6 276 ( 2 . 1 79 )+(0.71) ≤ -1.3675404+071 ≤ -0.6575404 ≤ -0.66 ≤

μ1− μ2

μ1− μ2

μ1−μ2

1

−x 2

( + T crit )+( ´x 1−´x 2 ¿

≤0 . 6 276 ( +2 . 1 79 )+(0.71)

≤ 1.3675404+0.71

≤ 2.0775404

≤ 2.08

≤ S x...