For multiple choice problems 1-10, circle the correct response.Each of these problemsis worth 1 point.

1. A study was conducted to investigate the association between smoking habits and incidence of lung cancer in trucker drivers.500 truck drivers were recruited and asked about their smoking habits.Theyfollowedthetruckdriversfor20years.Thisisanexampleofa:
   1. Cross-Sectional survey
   2. Prospectivecohortstudy
   3. Case-Controlstudy
   4. Randomizedcontrolledtrial
2. Whichsummarystatisticismoresensitivetooutliers?
   1. Themedian
   2. Themean
3. Prevalenceisameasureof:
   1. Interestofstudentsinthesubjectofbiostatistics
   2. Percentageorproportionofindividualswithdiseaseatasinglepointintime
   3. Thevariabilityofthepopulationofinterestinoursample
   4. Thelikelihoodofdevelopingdiseaseamongdiseasefreeindividualsatrisk
4. Onepurposeofstatisticalinferenceis:
   1. Tomakeinferencesaboutsamplesbasedoninformationfromthepopulation
   2. Tomakeconclusionsaboutapopulationbasedoninformationfromasample
   3. Todescribesampledatawithsummarystatisticsfromthe sample
   4. Todescribepopulationdatawithsummarystatisticsfrom the population
5. Whichofthefollowingisnotavalidwaytowriteanalternativehypothesisforoneproportion?
   1. H_a:p/=p₀
   2. H_a:p/=p₀
   3. H_a:p>p₀
   4. H_a:p₀

1. Supposea95%confidenceintervalfortheproportionofAmericanswhoexerciseregularlyis

0.29to0.37.WhichoneofthefollowingstatementsisFALSE?

1. Itisreasonabletosaythatmorethan25%ofAmericansexerciseregularly
2. Itisreasonabletosaythatmorethan40%ofAmericansexerciseregularly
3. Thehypothesisthat33%ofAmericansexerciseregularlycannotberejected
4. Itisreasonabletosaythatfewerthan40%ofAmericansexerciseregularly
5. Nullandalternativehypothesesarestatements about:
   1. populationparameters
   2. sampleparameters
   3. samplestatistics
   4. itdepends-sometimespopulationparametersandsometimessamplestatistics
6. Considerarandomsampleof100femalesand100males.Suppose15ofthefemalesare left-handed and 12 of the males are left-handed.What is the estimated difference between populationproportionsoffemalesandmaleswhoareleft-handed(females-males)?Select thechoicewiththecorrectnotationandnumericalvalue.

(a)p₁p₂=3 (b)p₁p₂=0.03

(c)p₁p₂=3 (d)p₁p₂=0.03

1. Arandomsampleof25collegemaleswasobtainedandeachwasaskedtoreporttheiractual heightandwhattheywishedastheiridealheight.A95%confidenceintervalfor

_d=averagedifferencebetweentheiridealandactualheights

was(0.8inches,2.2inches).Whichoneofthenullhypothesesbelowcanberejected?

(a)H₀:_d=0.5

(b)H₀:_d=1.0

(c)H₀:_d=1.5

(d)H₀:_d=2.0

1. Supposethata95%confidenceintervalforthepopulationproportionofmeninacertain age group who are overweight or obese is 0.25 to 0.35.Which of the following is the best interpretation of this information?
   1. 95%ofthemeninthesamplearebetween25%and35%overweight.
   2. About 95% of the population of men in this age group are between 25% and 35% over-weight.
   3. Wecanbefairlyconfident(about95%)thattheproportionofmeninthispopulation who are overweight or obese is between .25 and .35.
   4. Wecanbefairlyconfident(about95%)thattheproportionofmeninthesamplewho are overweight or obese is between .25 and .35.

1. (10 points) Among a random sample of 1003 students at a certain college, 827 favored banning smoking on campus.
   1. (5points)Whatisthemarginoferrorforthispoll?

1. (5points)Canyouconcludethatthemajorityofcollegestudentsatthecollegefavor banning smoking on campus?Explain.

1. (5 points) A clinical trial is conducted comparing a new pain medication for arthritis to a placebo.Participants are randomly assigned to receive the new medication or a placebo.The outcome is pain relief within 30 minutes.A 95% confidence interval for the risk difference (newmedication-placebo)inpainreliefis(0.08,0.30).Interpretthisintervalbystatingwhich group is more likely to experience pain relief and by how much.

1. (10 points) In an AP-Roper Poll, a random sample of 600 adults in the U.S. was asked "Generallyspeaking,wouldyousaythingsinthiscountryareheadingintherightdirection or in the wrong direction?" Of the 600 respondents, 56% said "wrong direction." Is this sufficient evidence to conclude that a majority of U.S. adults think things in this country are heading in the wrong direction?Answer this question by carrying out an appropriate hypothesistest usinglevel ofsignificance=0.05.Besureto performtheusual 5stepsto hypothesis testing.