Exam 2 - PS'i'C 2D13lFall 2011 Exam r42 Nmnr General...

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Unformatted text preview: PS'i'C 2D13lFall 2011.) Exam r42 Nmnr': _ General Llia1I~>L1it>I1a:WIElr wur Hume ohm-e. Writs: all answers on these pages. i-or Multiple-choice items, their; your an swer choice If you change your answer, ma let it Lin-Ir wlI-Il your final choice is. He sure to show all work you oid to mme u]: wiLh your an mere; if you make math errorsr you malt Hml‘rhr'ls'sfi Et‘T credit iF '.I'|:|'L=' followed the correct procedure. If you tend to he rnessalr, please underline or put holes around 'p'CIL'T answers [I'IIL'uPI'EI'IElt'ss riluasl: tn.- to write neatflrl. There are If? possible points; your were will l1I' the [Rummage of these point: that you earn. Good iutli! PJ‘lHTl Multi le choice uestio-ns- each robin-Ms point value is indicated before the nrablem For this part of the test. for tech question choose the one best answer. 1] [2 points] J‘- bd||1PliHfl tlislliisulitsn u:l means consists of r . t '--"r a. all the scores contai nod in a particular 53 mple h. all the tron-t. rxirituinud in a 5 pacific population LI". jhe sample mean.“- ior all Elm put-bible re ndtlm samples lof a specific sizel from a particular population the sample means for all the possible random i,::urnp'il_‘i,' tfur all saw- ple sings] from a particular pnpuletign .-" 2i l1 paints] In a hypothesiz- Lcst using I, the "critical region" [the I-sscu “'2”: [bill haw: an absolute value greater than or equal in. I” I] consists of / : L/ :1 sarrltllt' values lhat are very likely" to he obtained if HiI rs trotL 'I Cg: sample ad'suEL that are very unlikely to be phtainelj if Ht, is, true (EL Esample traiues that provide proof that H... is lEIIQ sample values that provide proof that i-I;I is false 5:! :2 points] .u'tseurrle ".lI.J1. :J 11u1rr|u|lllr distributed population hasp - EII'J and a: ZIL lfygu tout: dil uptgib'lu Hrs-pies Elf size n- ; 16 rrorn this population. and found the mean for each sample, the mean at all those wean: mum be . u r[aux] I-‘l e. EBB :_ '3:- W i. 1 r at .3. cl. 'e- .a-{iy ra n't be r. etermincd =1] [2 palm] Asst: me that a normally distributed popuietion has = .ti and .-r = 311. IF upu melt alt possible- samples. pf size n .— rLf 15 from this populatinfl, and inuht! The Int-an for eaeh sampler the standard deviation ofall those meant. wuulrl be a 3'4 t sh... ' n e. Elli-l l:I SCI i‘ 1 t:. 74 J [I .5; -- E h it. can't lut- dthttlrminptl 5i {2 points} For an indepen dent-5a mples study, the value of cam-.3 d h tips In: describe a. the risk ofa Tuuu I erroi h. e rlsx ofa flrue II eurur c. i'ID'lN much difference there is between the mt: trepth rm; :1. whether the difference between the two treatments is liker 1n l'IEI'L'r: umtlrmd tr,- chance El {1 polnlsl which of the [pi luwin}: dost-risz the effect ofincrea5.ng the alpha level (for eica mpte, frw_.t]11_u .051! 1'2 ._ 3’" a? increase the likelihood of relecting HE and Increase- the risk pf a. T'f'pel error ‘ decrease the likefihood of reJ'F-cting Hg and increase- the risk of a Type lurrur "-1? c :- rga“ increase the likelihood of rejecting Hg and decrease the risk ofa Type I en- m ' _ dt'nt'a'se the likeiihoo-d of rejecting H" and o'eL-rease the risk ofa lyrpe I error 5—K Kill-iii" .r-I I 4'] 5] ear. [1 points: When is there a risk of a T'l'pel error':1 @jfit'henever Hg is rejected ls. whenever Hg is retained c. whenever H; is reiected o. the risk mi in Type1e1rerisindeot-ndentofthe Ij I:I:i siren from .0. llypu‘. hear. Eleni [Z polnlsa which pfthe following mi N Increase the power of a statistical test? lChange alpha fren' .CIE to .411. {ha nge from a one tailed test: test. a. is. re}, Change the sample size from n = 25 p:- n — l-EIIZI. p a twp toil-col oi. None of the above. PART II fisher: answer and "word-Eroblem" Wtilfljflifl] Eroolem’sjeint sales; is inflieeted before the pr poleori til ___ e' 11]] L4. 11] 6 [5 points! Answer the questions help-air with respect to a normal population With 14 = 90. o = IJ. a. {3] What is the probability of obtaining a sample mean greater than BE For a random as moll' with n = 41 some-s? 5 ' '1 E1 i. 'k . p3 - -_ — : .. _ s . _ _ . 1.;- L } Jib _ _I-.|:__'IEI"-qufr_z _ 'I'L, ' 5’. CI _. : “L's-f. = —_-—— - a h. [2] If n were greater than 4. say what would happen so the probabflitv in part a [would itfio up, down. or stay the a} some]? IBeIiell'ri say win.r we LlH'JSI: your answer. L—r' . -' - . .. -. '.--;-~------ :. ’3 :«. ' -_—- - - e we: is .:-- 3' - :Ic' . “9* —. =+ 3&3.- .I thin-J's .5 'I' f" '_-. '_ .. ' .J--' u Eg._-._ etc: xC'l- Call '52.: "4-: '- '- we . -- .- -u if,- sif— |4 paints] |:1diLa:e-.r.rlle1|1er the feline-wing statemenss about the standasd error of the mean [EH] are tsue cur false. The- uI-anul-ascl Hrmr of the mean is a standard deviation. 5 I in: 11 The stanrlard error nf The mean roughly meawres the fepatal amount by which The TI. r‘hims nfsampies taken from a population elemate from the population's mean. T'f‘ E c. The standard error of the mean measurestnarialsilil'a.I in a particular sample. T": :11: __ _ __ o. The standard error ol the mean increase: in value with larger somrfie vices. "-_'_.___._'_~‘:_L {6 points] Eve-semi l'aetclrs influ ence the ‘ualue obtained For the independent-samples 3 statistic {that Fs. tmj. Some factors affect the hem eratprand pthers influenpe the denominator. For each of the lpilowine. indicate the circling epor choice] whether thcfnnur influonncs the nu rnurillrar or denomination 11‘. His;- r statistit: and dtrl¢ra11irm wlu—s'lllee: 'll‘lH Effect wuulc‘l L1H Iu lrlc:reNIM- the wine uft [fartIu-er from zero] or decrease the value- of t [cipser to zero]. In each case, assume that all other factors remain constant. a. :2} Decreasing the differenc etween the two sample mear-s .. E affeeE the/mus? pr denominator pauses 'm et _fer s 7p m. smaller in. {1} Decreasing: the size of the two samples affects the nu merator prfdenominatEFj :2] Decreasine the size of the sample enhances ' - —_—"—||. r dtrlflrfillfiflflEJ / r'—.—~— causesflo‘efimeeflr [to gel smaller causes. [_lr_1 gel. higggr Desi-ED get Ema—"EFT: L'. a—. L,» affects the nu merelor p 12] {3 points] Research suggarts that children with AGHEI tend to watch more "N than child ren who are not diagnosed with the disorder. To examine this, a researcher obtains a random sample trl n = 36 children [ages 3 lo- 12 sear-si- whcl have been 3-1 diagram-rd with Mill ID. lads. child is asked To keep a journal recording hnw much time each day is spent watelitng 'I'u'. The / average inr the Lilitplfl is M = ILEI hoursa'da'p. It rs known that the average time for the general population of Beta-1 I-Il'ear- old children isp = 4.1 hoursfda'f with cr = 1.3. is new associated with an increased angourit of W—watd'iing? EM. 3 a. in What kind of hypothesis test is appropriate here? 3 '9‘”? I'E‘ ' ‘3:- I " ' :3 I ' “'fl’!’ i. is. ill Brief-“hr describe the population being studied. ‘ ' “(P-E, _'.._-,|i__L!_ “.7in _ .".'-_ ,_ I.I'-;'. T: :'_I ' a: _' ~ ._" - ' . ‘3 v" i t.. I. }\lU!.i'_,-{4IP¢LJ*;.: LL": “if; :‘l'fii -_ Lip-7L3.) M 'j . :-__:_‘:_ _ __Lé__.' k _ e. E] State the null and alternative hypotheses in plain Engiish. L' : 1 .. . _. . ._ . itfl. -..I t I . .- 1. .- . u I — f. [1} what is the critical traiue of the test statisticr assuming :1 = .IIIEEI lie sure that this is consistent with whether H; is one- or two tailed. If you use df to fincl this value. please report it. . ‘1 13| 13 point-sh fissurnc: Lhal. riusrrlal buds} [elaspuralu rt: lur llii:::.,5l'.h',,I humans is 936‘ F. lffliglfil'l'lt.‘ Li'iul. “It: are irate-rusted in seeing il living long-term in a. Iren- cold environment is associated with a. lower lapel-Ir oernperature. in. group of 25 people who lien-e .I worked in Antarctica for at least three months have their body- temperatures measured when theyr are heaEthyr, an cl the ' mean at their temoeratu res is found to be 9?.4' F with a standard deviation ol1.5.ls the lJCIIZl‘g." tetn perat-ure of those with lung-term thptnurle 1.” .I liner},- told Hrwilfinrnenl lllilwllr than that Iii humans. in general? '- a. [ll What kind of hypothesis test is apprepuiate here? 43"?” ‘ ‘ M:.-' . 2‘ "'- "' i '“ “If I b. 11! Briefly descrihethe population being studied. 1.11% pfiflu all": :2. I__ at}. I m _ I“? . I .:- - I- :_ _ I, J J has. . .r - ' ; vii-33.1? c1; ‘ - . . . '7 I; c. lllwhacisthe dependentuadahle? '- ‘- __. '.'_‘ - __ : a' d. 12! Stole the rrull and alternalit-‘efreseart'h lnrpotheses in terms of parametersfsyrn hols. . I_ .- . I'M-UH - U FI?;..I_E__I_-:_ IL. -. t..- ..I-l [firLglé' r-IIIII- In" - I "-i- A—‘—‘. vrfi— W- a I i. e. [2] State the null and alternative hypotheses in plain engiish. ' .I - '- x __ .'h- I '-.' _-'- .'-. . .'- _ Iijr _-:_-— 'J-t:-.I._.,__ ..I . I__ I.- - ‘E I . (If 1/ i. [1} whm is the critical traiue of the test statistic, assurning or - .EIE? lie sure that this is eansiscent ' II with whether Hi is one- or two-tailed. If you use ile to find this value. please report it. "E 14: :9 points] .n't research er would like to era mine how the chemical twptoohan. contained in Foods such as turkey, can affect mental alertness. A sample at n = El- tollege students is pistai necl and each student's perlprmante on a familiar eicleo game is rrleuwred before and afte: eating tI traditierldl 'l'henltst-titrinr: dinner [irltlutlinfi Lurker] The average more dropped by .|'I-'l= 14 points often the meal with 55 = 1133' for the diiierente scenes. I: inlet-391mm associated with: u ehanfie in mental alertness? "I it E. r, iJ. -: Li. L'. '3' I...- r. .= f: .5- t nona- '- _ - . 1 _,._. Fl”"”,. {1] 1t-‘i'hat kind of hypothesis test is apptepriate he-re'. {1] 1.Nhatis the independent or quasi-independent variable? . :' .' " L s. at... {1]1u'li'i't.|lis1i1t' dependent 'tl:.;tri:|l::|t::-I Hoff}: -'. '3'" I {1] | low is the deperltier'at variable rrIt'asered? J: L..-'I . '_ " '_ _ - . . Hots, 1.2:;- ._ . --; - . - {2] Etate the null and alternativefreseorch hypothues in terms of para-metersfstrmlsols. I I z -. | fl _.g‘LL—‘Iil‘ifii’l t.____ _." f‘fi_ " |-. — '- 2 5 {Mi—5h {25 State the null til-Id ulternutiue hwptheses in plain English. I. hunt-1f J. - - ' t - _. _ Tuvalu {1: What is the critical t-a lu-c of the test statistic. a ssumingttr — .05? Be su ret’nat this is consistent with wheth er H". is one or two- tailed. It you use of to fincl this value, please report it. -~ 3' z a; lit- [9 [it-innii fit resetirt'heur t'urrtlt-‘t'ts an ex perirrlent to examine how serotonin ta chemical involved in neutal processes] is S retateei to aggression. Dne sample of rats serves as a control group one receives. a placebo that does not affect :I1urrrl.s| serotonin levels. :5. second samn"e of rats receives a clfugthat lowers blain ieeels of serotonin. Then the rfiearcher tests the 3m mals bl..- recordlne the nu mberefamressme responses each of the tats dis-plates. The tie ta areas Inflows-- Low serotonin M: 1!-] 55 352 h .. {I -_ {ii'u'tlhatistheindepenclentorquasi-inclepen-clenteariahie? _'5 ._".it_'- ' .' . ' ’ {1} What is the depend ent variable? ' Ill How is the dependent variable measured? [2! “State the Neil and alternatiuefresearc'h hypotheses in terms of paramemrsfsym l:Io|s. I .- -_ = _ I _l . Ft. / _' ..i—=.;'-.L.irF , I -' ' {Act/v '_'_'_——# SMJ' “5—- IZI State the null and ulten'nuti't-‘e hypothefifi plain English. MEX -te.- ... = ._Io._s .V ._ - .. s» _.- ' - - __ 't. (/2 1 s ‘ - . . . . t/- - ' . 1 b.fl_-f—UII.I .:I I “5.. E...:-i\ -3 __-.-:II__, .I_, Ix ' ' "K said“ -' l' «2’ "— —" L__ W —-'.'7=L Lee” til What is the critical value of the test statistic. assuming ct = I2I5r1 Be sure that this is ten slstent with Whether H1 is one or twp-tailed. I! you use tfif‘ntl find this welt: e. priciest: report iT. of}: _ZI d Tulle; "I; It_-t ' ' 1— ‘-' 1'5] {12 DEFINE! Chflflfiem problems {and IIII'II'I' twoll ffflm arrlorlfi Problems 12-15 and perform the remainde: grum- Wpfithfiifi teal-ll mint-c ll": Uri lical val ue you generated to make a decision {thuut H“. Be sure 11:: 591ml: any :nmputatI-ans um. I. 1 6 perform. dearly label the chewed value of the test statistic. dead-r write your decisiun about Hg, and state a cmdusion I that mentions file pnwhflms being studied as well as the independemand dependent variables [make sure 'p'flur EOI'ICIUSiGI'I is Mt SEI'I'IF-hl' "Ffil'éfl Hu" ¢F"F:Ii114.1 mien Ha". but instead an answer to the FDGK‘arch questionl. Also, iFthe null h‘s'lifllhflfiis i5 rEjE‘CL‘Ed. find Cohen's I'J'. [J'lfi-Sume that all uniumptiuns underlying the use affix! F-TESI' Du PILL-5|, urc met} '_-. -E i I ._ ?- .J—I - .--a ji'=_':"1=1'-| i; J?:Efi __ II; .5 P I ,2: _-___;;_ :HUI flnF : F _ b 1w1-HEJ;I-_.E}d_ -~u—\ld__ ‘1‘: 1;: =3 lib-1.: — _. .|'_— n. . r~ a'fi d— --t n. I. _ ~JIX'..I__ J "ix—ll“! A H _~' " “fie-:5 i-;:‘*‘; 7":I ‘-'~-‘ ' -" I———'fl : IG- _ _ H d= we“ LL13 _ w A; Laval-Luv cw - a u '" - E. *- l5; _ |—_ —l ...
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