Class Notes (1,100,000)
US (470,000)
NKU (40)
STA (10)
STA 205 (10)
Lecture 5

STA 205 Lecture Notes - Lecture 5: Confidence IntervalExam


Department
Statistics
Course Code
STA 205
Professor
Brooke Buckley
Lecture
5

This preview shows pages 1-2. to view the full 7 pages of the document.
12/17/2018 NKU Imath Assessment
https://imath.nku.edu/course/gb-viewasid.php?stu=11461&cid=335&asid=149931&uid=11461 1/7
Grade Book Detail
Damico , Emily
Topic 5: Confidence Interval for the Proportion
Started: October 1, 2018, 12:45 pm
Last change: October 1, 2018, 4:59 pm
Total time questions were on‑screen: 139.1 minutes.
Showing Scored Attempts | Show Last Attempts | Show Review Attempts
Hide Correct Questions Hide Perfect Questions Hide Unanswered Questions Show All Answers
Preview All
Mobiletechnologyhaschangedthewayconsumersaccessinformationandentertainment.In2014,itwas
reportedthat47.8%ofsmartphoneusersbetweentheagesof18and29regularlyusetheirsmartphoneto
watchmoviesorTVthroughapaidsubscriptionservice(suchasNetflixorHulu).ThePewResearch
Organizationundertookastudytoseeifthispercentagehaschangedinthelastyear.Arandomsampleof
279smartphoneusersinthisagerangewasselected,anditwasfoundthat147ofthosesampledusetheir
smartphonetowatchmoviesorTVthroughapaidsubscriptionservice.Testtheappropriatehypotheses
usingasignificancelevelof0.10.
    
= decisionrule:reject ifprobability  
TestStatistic:z= (Note:roundthezscoretotwodecimalplacescarryatleastfourdecimal
placesthroughoutallofyourcalculations)
probability= (Note:roundtheprobabilitytofourdecimalplaces)
decision: 
Conclusion:Atthe0.10level,there  significantevidencetoconcludethe
percentageofsmartphoneusersbetweentheagesof18&29whoregularlyusetheirsmartphonesto
watchmoviesorTVthroughapaidserviceis than47.8%.
Answer:p
Answer:=
Answer:0.478
Answer:p
Answer:≠
Answer:0.478
Answer:0.10
Answer:<
Answer:1.64
Answer:0.101
Answer:FailtorejectH
Answer:isnot
Answer:differentthan
Question 1: 7.5 (parts: 0.25, 0.5, 0.25, 0.25, 0.5, 0.25, 0.5, 0.5, 2.5, 0, 0.45, 1, 0.5) out of 10 (parts: 0.25,
0.5, 0.25, 0.25, 0.5, 0.25, 0.5, 0.5, 2.5, 2.5, 0.5, 1, 0.5)in 3 attempt(s)

Only pages 1-2 are available for preview. Some parts have been intentionally blurred.

12/17/2018 NKU Imath Assessment
https://imath.nku.edu/course/gb-viewasid.php?stu=11461&cid=335&asid=149931&uid=11461 2/7
Supposethefollowinghypothesesaretested: versus
Whatistheappropriatedecisionruleforthistest?
reject ifprobability<
reject ifprobability
reject ifprobability>
Theprobabilityforthetestisfoundtobe0.1209.Basedonthedecisionruleabove,whattypeoferroris
possibleif =0.05?
TypeIerror
TypeIIerror
Ifthesignificancelevelwerechangedto =0.10,whateffectwouldithaveontheerrorabove?
ATypeIerrorwouldnowbepossible.
ATypeIIerrorwouldnowbepossible.
Therewouldbenochangeinerror.
Answer:reject ifprobability<
Answer:TypeIIerror
Answer:Therewouldbenochangeinerror.
Question 2: 5.8 (parts: 2, 2, 1.8) out of 6 (parts: 2, 2, 2)in 3 attempt(s)
Ifthelevelofconfidenceincreases,theconfidenceinterval:
staysthesame
getswider
getsnarrower
Note:Youmayonlyattemptthisquestiononeadditionaltimeandapenaltywillbeassessed.
Answer:getswider
You're Reading a Preview

Unlock to view full version