2 To plan properly for equipment and services during the upcoming year Comcast

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2. To plan properly for equipment and services during the upcoming year, Comcast would like totest the hypothesis that the average number of televisions in the homes of its customers is equalto 2.9,3, The federal government would like to determine the effectiveness of a recent tax-break proglamfor first-time home buyers, Prior to the tax break, the average time period a house was on the mar-ket was 60 days, The government would like to test the claim that the current average time on themarket is less than 60 davs,
The only two conclusions (statements) we can draw are:Hypothesis testing relies on "proof bythe null hypothesis and we can then conclude that the -l,tf is true._ the null hypothesis and we cannot conclude that the is true.". The author uses the analogy of our legal system tothe null hypothesis. Instead we say that we1. Type I Error: Oec\r"cs N0'4 -{\o is cll'{&-d' *Oto^, u^ rt"fu\2. rype ll Error: oceufs e,rftrr * ,"il tt f<fe+ -{tb t'*u^ /The only way to reduce the risk of making both error is to tne {-t a (Q- the sample size.tWe will look at how to perform hypothesis tests for three scenarios:explain this concept. Ultimately we neverThere is always going to be a risk of drawing the we are using data from aSC'nfto to draw conclusions about theThe two types of errors we could make are:Section S"?S*sticn S"3Sectlcn S"4
9.2 Hypothesis Testing for the Population Mean when o is Knownstep!- Stt a- \$a'l^rn- t* fu tcXnr{roal 'Qlw'U,<tepa t0'.r- ^1gtogr-ratc cr''\eJ \"lu.t't' tt<,{,1 tt^t ^'1t *A, "t\.tnrfi,"" \f"tf;'os.s, One-Tailed Test: Find z-scor" .t *- in the tailTwo-Tailed Test: Find z-score witn s(/2 in the tailIM," get the critical z-score.We can use the excel functionStep 4:TEST'l\$,o-tltilOne-tnil( upper)0ne-ttil(lou'c't')llIP0TllESl\$ ' :.1'' ooNDlTloN ' :.ii,Hrl.t;-: t\t l:-l .r' l:.,,,:l -->H; p" *.p4 - l:ul s i.",: | --->HQ: /.r. < trIt) i.r .> in,Hrr&>l,kl i,.Sio -Hn:prpq' .,r{ -1., *-+H; 1t 'i pq' :; * 'i,a ---->Do uot reject fd;Reject ffoI)o not reject H1.Reject H,,Do not leject fl,step5: c'r,?r=^-{- 7-tts{ stot.,shc- E") tli{L ttt erthca'L z-scor{-(o )3 faglg 9.3 | Declston Rulss roR. HYpo"rltssts Trsrs WHsl'{ CoN4PARING rHEz-Trsr Stcrlsrtc (z1J r'vIrn rHt CRtttcArz-sconr (zn)Step 6:
Together we will work this Problem:Yffi&\$ffi ry&\$ffiffi #2Lindsay is the manager at a local Ruby Tuesday restaurant and has implemented changes to heroperation to reduce the average wait time for a table between 6:00 p.ur. and 8:00 P.M. on Saturdaynight to less than 20 minutes, A random sample of 45 wait times on Saturday night had a mean of1d.3 minutes. Lindsay knows from past experience that the standard deviation of wait times is5.0 minutes. Follow the steps in the previous section to determine if Llndsay's changes havereduced average wait time to less than 20 minutes using a : 0'05'Your Turn:Bob's Sporting Good.s believes

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• Fall '14
• Null hypothesis, Statistical hypothesis testing