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Unformatted text preview: ID: __________________________ __ Quiz section or time: __________________________ __ Stat/Math 390, Autumn, Test 1 — Oct. 10, 2008; Marzban H + [5
Open everything, closed messaging/ discussion
Check front page and back page.
Multiplechoice: mark answers on these pages.
The rest: SHOW your answer and your WORK, on these pages. Points NO CREDIT FOR CORRECT ANSWER WITHOUT EXPLANATION. 1 1. Let x be the number of correct answers on a test with 4 multiple—choice questions, each with 3
possible answers. The mos propriate distribution for describing this variable is
a) Normal inomial c) Poisson d) Exponential
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1 2. For a given data set, is it true that a value of x three standard deviations from the mean is
farther away from the sample mean than a value of x two standard deviations away from the sample  an? Mark the most appropriate answer.
lways yes. b) Yes, but only if data is Normal. c) Yes, but depending on the data. 1 ? LS 3. or a continuous variable, x, the proportion of times that a speciﬁc value, x0, can occur is equal 0 the value of the density function at $0.
a) True. b) True, but only for a Normal distribution. ﬁnitely false. TL" \DmP 0(2)“):0 \oLCUMH—m avw DVC—‘r 0‘ Phi/CV 1 A paper reports that the number of defective transistors across square bentimeter of an
Wtegrated circuit follows the Poisson distribution with A = 100. But you are interested in the
distribution of defecti ransistors across half of that area. What value of A should you use?
a) 100 @ c) 200 d) Insufﬁcient information provided. 2 Ml 5. ompute the median of an exponential distribution with parameter A.
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5 A9, .L, = r :» ’Ae = r
7. o 7.
o ’ 'A C—qc 1 ’ F"; :V ET'AC: 1 => [ACTAm) _ Z. 2 @Suppose that the reaction temperature x (in C) in a certain process has a uniform distribution
etween —y (C) and +y For any temperature T satisfying —y < T < T + 2 < y, what long—run
proportion of temperatures will be between T and T + 2? R14] 1
L >1 «3 (T(X<T+2)
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9L; 7. Wine is considered to be properly handled if the storage temperature is within 1 standard eviation of the mean. If these wine bottles are shipped in batches of 20, in the long run what
proportion of the shipments will have at least 19 bottles that are properly handled? Give a numerical answer, and show work. _ voq’L + ID‘QOLl 7C: :ﬂrsf {Nora/l1 Lamilbé “+er gjjf‘ 2V /1 ;@ WWW) = v<><=m>+vb<=w) — t?) w“ M); (:2) 77“ 07)“ .a ‘ (7 to m I? 1'“
—207 “2077 r7 :ZDFZ—liﬂ,
7]: Fray. 2’} flora/(7 LmNHLJ Lh'H‘lU + K ‘— :_ QVUZ Ukwkev Maw/Li Wf‘lﬁr'n i (lidv 4WD“ : . Zra /
— ffvytxzm) : 10(0.68)l1—L1C0.63) : 0.m5\—o<>8a1oo%i
[email protected] x denote the maximum physical stress that a unit of a certain product encounters during ' s lifetime. Suppose that x is normally distributed with the 99th percentile = 5.33 and the 10th
percentile is 1.72. What are the values of the u and a of the distribution? Give numerical answers,
and show work. 6 3.61 :3.“ 0" =»[q=\i 3 . Consider a sample xzﬂ = 1, 2, ..., n with mean T, and standard deviation 5, and let 2%» = ($i—T)/S.
What are the mean and standard deviation of the 23’s? Show work. V\ __
W9 1?: : L i.) E; : J— r" x : J— __—~ ~ ...
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This note was uploaded on 10/17/2008 for the course STAT 390 taught by Professor Marzban during the Spring '08 term at Washington State University .
 Spring '08
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