Class Notes (810,429)
Canada (494,121)
QMS 202 (64)
Clare Chua (13)

Lecture 4

4 Pages
Unlock Document

Ryerson University
Quantitative Methods
QMS 202
Clare Chua

1/30/2011 Howtomakestatisticaldecision? Lecture4 HypothesisTesting:Onesample Ifa.05levelofsignificanceisusedina(twoH tailed)hypothesistest,whatwillyoudecideif thecomputedvalueoftheteststatisticis +22.21 Objectives: 1. Hypothesistestforµ when isunknown(tHtest) 0.025 0.025 2. Hypothesistestfor5 Z -1.96 0 1.96 +2.21 Note: the assumption, that doesn havemean we ignore it. We to consider it at all times. Hypothesistestforµ when isunknown tHtestt Onesample THtestofHypothesisfortheMean • Ifwedonotknowthepopulationstandarddeviation,  Hypothesistestforµ • Weusethesamplestddeviation,s. when isunknown • IIweeassumeehaatthepoop.snormaalydisributed,, thesamplingdist.ofthemeanwillfollowat distributionwithnH1 degoffreedom. • IfthepopisNOT normallydist.,youcanusethetH testifthemplesizeislarge(n>30)enoughforthe THtest CLTtotakeeffect. 1 1/30/2011 EXAMPLE tTestofHypothesisFortheMean(8 Anewbatteryhasbeendevelopedtopowerlaptop unknown) computers.Itwillsellinacertainpricerange.Itis hopedthatthebatterycanbeusedformorethan x 2 4.00hours beforeitneedstoberecharged.Wewill t assumethatthebatterylivesarenormally s distributed.Arandomsampleof50batteriesis testedd.Theesamp plebaatteriessasteddanaaverrageeoff n 4.12hourswithastandarddeviationof0.25hours beforetheyrequiredrecharging.LetH=0.05 Where the test statistic t follows a t-distribution having n-1 degrees of freedom SAMPLEMEANANDSAMPLE STDDEV(s) Whattestdoyouperform? Ztestorttest? ThesevenHstepMethodofHypothesisTesting Steps (or the thought process) 1. Identifythevariableofinterest,Xor… 1. Clearly identify the variable of Let X=the life (hours) of a battery. 2. StateNullHypothesis,HoandAlternativeHypothesis,Ha interest. 3. Determinetheappropriatetest(refertotheflowchart) 2. Null Hypothesis Ho: µ=4.00 4. Statetheassumptions 5. DeterminethecriticalvaluethatdividetherejectionandnonHrejection more than 4.00 hours? region Alternative hypothesis Ha: µ>4.00 6. Calculatetheteststatisticvalue 3. Determinetheappropriatetest(reT-test 7. MakethestatisticaldecisionandManaalconclusion. totheflowchart)Hgiven 4. What assumption(s) are made to None since n>30 perform this test? 5. DeterminethecriticalvaluethatdGiven 5% significance level. therejectionandnonHrejectionregion A one tailed test 6. Calculatetheteststatisticvalue/pHvalue Use the Casio Calculator 7. Makethestatisticaldecisionand Managerialconclusion. CFXH9850GBCalculator Ho: µ = µ0 Two Tailed Test Ha: µ  µ0 ,/2 ,/2 Lesson9– tHTestofasingleMean STATF3(test) F2(t) F1(1HS)thenenterthefollowingitems: (Noaccidentallyhitthewrongkey,useAC/ON orEXIT togoback.)thecursorz arrow.Ifyou Rejection Region 1HSampletTest Rejection Region Data :F2(Var)z … :F3(>)z …0 :4EXE Ho: µ = µ ONE TAIL TEST x :4.12EXE 0 RIGHT Tailed Test , nnH1 :50EXE Ha: µ > 0 NowkeyEXE orF1(Calc) Rejection Region Thecalculatorwillnowshowtheresults: ONE TAIL TEST 1HSampletTest Ho: µ = 0 t =3.3941 Ha: µ < 0 LEFT Tailed Test , p =6.85
More Less

Related notes for QMS 202

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.