Review Ch.

7, 8,9

STA 2023

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f ±Z¥pF'¥ H Z¥=Zo÷=Zo .us t.at#o_O

- 1.46 1.96

£0' ' 73

0.1731=1 .gg#ctE Interpretationn= 200 200

-

0.173+-0524 We are 95% confident that the

proportion of adult Americans who→ ( 0.121

, 0.225 ) ← Confidence intendplanned to purchase a Valentine 's Day

lower upper

This is interualnotadion.

Gift for their pet is between

0.121 and 0. 225 .

b.) The interval would be narrower because we are

dividing by n. Larger n= smaller SD

Hypothesis TestingForm of a null hypothesis:

Ho : population characteristic = Hypothesized value

( p or n )

Form of an alternative hypothesis :

Ha : population characteristic Hypothesized Value

Ha : population characteristic Hypothesized Value

Ha : population characteristic Hypothesized Value

a.) Ho : P=o . s ts . z= 5,1-0-5Ha '

. p > o . s o.scto.si= 2.53

( oo 0

R 'R

. we 'll reject Ho if 2 > Za = a. a = 2.33

2. 53 > 2.33 ✓This statement is true.

Reject Ho ! At the Q=aa significance level, there is sufficient evidence to indicate that a

majority of women ages 22 to 35 who work full the would be willing to give up some personal time

for more money .

Ho : p= 0.68 FS.

z = 0.84 - 0.68

Ha :p ¥0.68 .gg#@= 7.76

512

R.R. Wein reject Ho if 2 > Zoz = 00=5--0.025 = 1.96

or if 2 < - 2¥ =- 1.96

or7.76 > 1.96 ✓ True

of 7.762 - 1.96 X

Conclusion : Reject Ho ! At the Q = 0.05 significance level there is

sufficient evidence to Indicate that the proportion Freligionssurfers who belong to a religious community is different from 0.68

.

so, are need to use

we +.

Ho :

M= 138

Hai M > ( 38 §anp1emem= , 45.3we don't have

Population mean = ( zgof rrutionsp

On.

ST=X-n-= 145.3 - 138

s - = 2.69nF 17.6

EL

RR_#aA⇒ayEgI±:±# if

Q= 0.01

R We need to use the 98% *t= 2.42 column on the + table ! There

thatwelookedm wpu be /% on the upper Hood

on the table .

Conclusion 'D.GG > 2. yzend

,and we will round down to df=4o .

Reject Ho '

. Attlee # significance level

Here is scariest credence to indicate that the mean

blue altar IHD pressure exceeds 138.

THEY:* .

what's among with this

No : n= 22.0 .ae ssofmfefthfnthdeg.ge

Ha'

. M =/ 22.0

saethe average down

.

T 's'

+ =T¥;L=27EsI= 1.83

Too two tailed test bk # .

# Qa±¥f\9=aa we 'll reject Hoof## + > fdf

¥299o.O F 233

/ -83>2.

zzxor if t←tYo?*= -2.33

1.83 52.33 XConclusion : Do Not Reject Ao ! At the a -0.02 significance level

there is insufficient evidence to indicate that the

mean alcohol consumption for Washington Dcresidents differs from 22.0 gallons annually .

@ Define P , t Pz

PIproportion of men who expect a rise this year = as 2

poemproportion of women who expect a raise this year = 0.37

( Ee)±z±.mn#+mtF

Nw

= > (0.52-0.37) ± 1.go.EE#totsyIF

= > 0.15+-0.06

=> @. 09

, 0.21 )

Interpretation : We are 95% confident that the proportionof men who expect ataise this year is

between 0.04 and 0.21 greeted than

the proportion of Women .

Testing Hypotheses about the Difrerence Between TwoPopulation Means

Ho : M ,-

As= hypothesized value (usually 0 )

" what we're testing "

Ha'

. M,

- Mr< hypothesized ValueGris lessthan 2)

Hoi.

M,

- A> hypothesized Value (mi is greaterthan . )

Hoi.

Minn¥ hypothesized Value (m , divers from

A)Z - approach may be acceptabledepending on instructor / textbook .

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's

ttIII÷fe:IE÷÷ ' ' 43

I÷IEe←e¥ .net#IE:EIIEiI:Ei:

I.EE?EIxxNopd.

Conclusion : Do not reject Ho ! At the a=o . os significance level there is insufficient evidence

to cndesate that The mean reaction time for draws talking on a

cell phone differs from those who are legally drank.

Testing the Difference Between two Population Means using Pairedsampk

Ho : Ma = hypothesized value Md is the mean difference in the observations

Hai Ma < hypothesized value

Md=MMz

Ha : Ma > hypothesized value

Ha :

Mathypothesized value

⇐ Enid:#sharp

⇐n¥i÷¥÷¥I÷⇐*÷÷⇒.

.IE#IItoIat.IIiiiiIY

contusion : rhythm.LI#tEoImIIIEthhas:IyYuEidItoandIEs.

Let

ME Score before the course

Let Ma = score after the course

Let Up = MA - MB

YI

:niEots.

t.YYGEEI-tyi.sn#=.4.se4

RR. We 'll reject Ho if t<

#III " " ±2.72

zed

-4.564>-272

ryes

Conclusion : Reject Ho ! At the K=o . a significance level there is sufficient

Yids:TakingEFFETE.IE#uYatIemIyhEnsmsmthan before .

Use 4=0.01

Mp =- 144.5833

Standard Deviation = 109.74

N= 12

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Questions?

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