1. TwentyfiveseniorsfromalargemetropolitanareaschooldistrictvolunteertoallowtheirMathSATtestscorestobeusedinastudy.These25 seniors had a mean Math SAT score of x= 450.Suppose we know thatthe standard deviation of the population of Math SAT scores for seniors in thedistrict is s= 100. Assuming the population of Math SAT scores for seniorsinthedistrictisapproximatelynormallydistributed,a90%confidenceintervalforthemeanMathSATscoremforthepopulationofseniorscomputedfrom these data is;

a.450 32.9.

b.45039.2.

c.450164.5.

d.nottrustworthy.

2. Informulatinghypothesesforastatisticaltestofsignificance,thenullhypothesisisoften

a. statement of"noeffect"or"nodifference."

b.theprobabilityofobservingthedatayouactuallyobtained.

c.astatement thatthe dataareall 0.

d.0.05.

3. In their advertisements, the manufacturers of a certain brand of oatmeal would like to claimthat eating their oatmeal for breakfast daily will produce a mean decrease in cholesterol of morethan 10 points in one month for people with cholesterol levels over 200.In order to determine ifthis is a valid claim, they hire an independent testing agency, which then selects 25 people with acholesterol level over 200 to eat their oatmeal for breakfast daily for a month.The agency shouldbetesting thenullhypothesis H0:m= 10 andthe alternative hypothesis

a.Ha:m<10.

b.Ha:m>10.

c.Ha:m10.

d.Ha:m10s.

4.Themeanareamoftheseveralthousandapartmentsinanewdevelopmentbyacertainbuilderisadvertisedtobe1250squarefeet.Atenantgroupthinksthismaybe different,becauseitisbasedonthe squarefootageofapartmentsin anolderdevelopmentbythe samebuilder.Thegrouphiresanengineertomeasureasampleofapartmentstoverifyitssuspicion. Theappropriatenull and alternative hypotheses,H0and Ha, formare

a.H0:m=1250andHa:m1250.

b.H0:m=1250andHa:m<1250.

c.H0:m=1250andHa:m>1250.

d.cannotbespecifiedwithoutknowingthesizeofthesampleused by theengineer.

5.Is the mean age at which American children can first read now under 4years?If the population of all American children has mean age of myearsuntil they begin to read and standard deviation syears, one would test whichofthefollowingnullandalternativehypothesestoanswerthisquestion?

a.H0:m=4vs.Ha:m>4

b.H0:m=4vs.Ha:m<4

c.H0:m=4vs.Ha:m4

d.H0:m= 4vs.Ha: m=4x,assumingoursamplesizeisn

6.You give the SSHA to 25 students who are incoming freshman and findtheir mean score.Assuming that the scores of all incoming freshmen areapproximately normal, with the same standard deviation as the scores of allcollegestudents, theP-value of thetest ofthenullhypothesisis

a.theprobability,assumingthenullhypothesisistrue,thattheteststatisticwilltakeavalueatleastasextremeasthatactuallyobserved.

b.theprobability,assumingthenullhypothesisisfalse,thattheteststatisticwilltakeavalueatleastasextremeasthatactuallyobserved.

c.theprobabilitythenullhypothesisistrue.

d.theprobabilitythenullhypothesisisfalse.

7.The Survey of Study Habits and Attitudes (SSHA) is a psychological testthatmeasuresthemotivation,attitudes,andstudyhabitsofcollegestudents.Scores range from 0 to 200 and follow (approximately) a normaldistribution, with mean of 115 and standard deviation s= 25.You suspectthat incoming freshman have a mean m, which is different from 115, becausethey are often excited yet anxious about entering college.To verify yoursuspicion,youtest thehypotheses

H0:m=115,Ha:m115.

Intestingthesehypotheses,whichofthefollowingwouldbestrongevidenceagainst thenullhypothesis?

a.usingasmalllevelofsignificance

b.usingalargelevelofsignificance

c.obtainingdatawithasmallP-value

d.obtainingdatawithalargeP-value

8.Inastatisticaltestofhypotheses,wesaythedataarestatisticallysignificant at levelaif

a.a=0.05.

b.aissmall.

c.theP-valueislessthana.

d.theP-valueislargerthana.

9.Ina testofstatisticalhypotheses, theP-valuetellsus

1. ifthenullhypothesisistrue.
2. ifthealternativehypothesisistrue.
3. thelargestlevelofsignificanceatwhichthenullhypothesiscanberejected.
4. thesmallestlevelofsignificanceatwhichthenullhypothesiscanberejected.

10.A university administrator obtains a sample of the academic records ofpast and present scholarship athletes at the university.The administratorreports that no significant difference was found in the mean GPA (grade pointaverage)formaleandfemalescholarshipathletes(P=0.287).Thismeans

1. theGPAsformaleandfemalescholarshipathletesareidentical,exceptfor28.7% oftheathletes.
2. themaximumdifferenceinGPAsbetweenmaleandfemalescholarshipathletesis0.287.
3. thechanceofobtainingadifferenceinGPAsbetweenmaleandfemalescholarshipathletesaslargeorlargerasthatobservedinthesampleifthereisnodifferencein mean GPAs is 0.287.
4. thechancethatapairof randomlychosenmaleandfemalescholarshipathleteswouldhaveasignificantdifferenceinGPAsis0.287.