# Annotated-InCa21

.pdf
STAT 35000 Name erint: D In-Class-Activity 21 Time Limit: 10 Minutes Instructor: ' This working sheet contains 1 page and 1 problem. Check to see if any pages are missing. Enter all requested information on the top of this page. 1. Avote is to be taken among the residents of a city and its northern suburb to determine whether a proposed recreation center should be constructed just northwest of the city (and west of the suburb). To determine if a higher proportion of suburb residents favor construction than city residents, a poll is taken. (a) (5 points) If 300 of 500 city residents favor the proposal and 280 of 400 suburb residents favor it, would you agree that the proportion of suburb residents favoring the proposal is higher than the proportion of city residents? Use an a = 0.05. HO: P,:Pz VSs. H1: , < F, Group1: (',r;j Res and Group 2: Subprb (222, Data: h' :500/ )(, ~ 200 é Assume:alpha= (05 P' s (Y Statistic: 7, =Hoo, x, =226 P - L& - '7 ﬂ, j- - 772_ N ' (6 -"76) 57 oren( 0 '07 = :{i——""""-- —————T" ~ =31 |544p] c=a ( 4'L/ ] *60O X YO ' 70441 1 36 = ) 6HY ST \ 906 —mo i P-v = f - . D' [HYC - . alue ] 2.4= -3 \l/_ m/J = pnorm(_ 2 (gqqo/) = 0°666306 4207 Decision: Fail to Reject / Reject HOat 4 _ 4, 65 Conclusion: [)tz 90(00'"'* eloipn Ao I'M'Z/ﬂc r pro //'ar"',"l'cr 6f subunk ol cd tovse Hu pospesal Hron @{4—9 P esiclents (b} (3 points) Redo the problem with a smaller sample: If 75 of 125 city residents favor the proposal and 70 of 100 suburb residents favor the proposal. Use an a = 0.05, | | | l ) =n'06737 = | 67724 | P. valus :pmrm(— | E77D L 0'07 7! \ ' c—o?'"'-'*!;m - ) #'-_-1_2" . ;6 'V& o= 1065 ! & S < ¥ Y ) P-VY? ; : | \ ' . HL'/'L/ _&'u'_'_p wj(,L "o 0,' X- '0F | (c) (1 points) Why the decisions in (a) and (b) differ. M dﬂ.&(.".bﬂf ;'n J»—l"l, Pfi(\ﬂ.oufi 2 fo\pv"'; dj'\c('(_(' CIV\L 40 ""H/'L dj{gpﬂdn&. | 3(\ -"u fioﬂf"' 5;24c' \A/I'M&L' (enese e !Jmnc'nm'l e0ner |in e \orl'enl. O - (d) (1 points) What is the meaning of alpha=.05? r - \ o U} 6 [N o LA Wearerisking a4 5 ¢ Pfiébabn 'l'lj o~ J'jfz I ere ¢, 6% 4") Ob | P{/ e e') I.fnj A "i'f'lu.'- H'o .