DSCI5180 Spring2013 Quizzes1-6
Transcript of DSCI5180 Spring2013 Quizzes1-6
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DSCI 5180: Introduction to the BusinessDecision Process
Spring 2013 Dr. Nick !"nge#opou#os
Exam 1 review:
Quizzes 1-6
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POP QUIZ #1
1. Probabilities under the Normal Distribution
are typically calculated:
A. After standardization of the random variable
. !"ter applyin re$erse standardi%ation
&. y as'in e(perts to estimate itD. )ithout the use o" computers or calculators
*. )ithout loo'in at a Z table
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POP QUIZ #1
2. ,he number that corresponds to a tail
probability o" - is usually calculated:
!. !"ter standardi%ation o" the random $ariable
B. After applying reverse standardization
&. y as'in e(perts to estimate itD. )ithout the use o" computers or calculators
*. )ithout loo'in at a Z table
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POP QUIZ #1
+. In pro$idin inter$al estimates "or 0 the tdistribution applies:
!. )hen sample si%es are lare n +34
. )hen sample si%es are small n 5 +340
reardless o" the distribution o" 6
&. )hen the pop. st. de$iation 4 is 'no7nD. When the pop. st. deviation () in unknown
*. )hen the sample st. de$iation s4 is un'no7n
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POP QUIZ #1/. P%14 and P%5 814 are related as "ollo7s:
!. P%14 9 P%5 814 1
B. P(z!) " P(z# $!)
&. P%14 3.- 8 P%5 814
D. P%14 9 P%5 814 3.-
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POP QUIZ #1
-. ,he probability that a consumer
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POP QUIZ #2
1. )hich one o" the $ariables listed you
e(pect to "ollo7 a Normal distribution:
!. ?i%e o" craters on planet @ars
. ?i%e o" earth
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POP QUIZ #2
2. )hich one o" the $ariables listed you
e(pect to "ollo7 an *(ponential
distribution:
A. +ize of ,raters on planet -ars
. ! personBs heiht&. ! personBs 7eiht
D. ! personBs intellience IQ4
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POP QUIZ #2
+. ,he &entral imit ,heorem states that:
A. When sample sizes are large (n )/ the
distribution of 0$bar is appro&. normal
. )hen sample si%es are small n 5 +340 the
distribution o" 68bar is appro(. normal
&. )hen the pop. st. de$iation 4 is 'no7n0 thedistribution o" 68bar is appro(. normal
D. )hen the pop. st. de$iation 4 in un'no7n0the distribution o" 68bar is appro(. normal
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POP QUIZ #2
/. In statistical in"erence0 7hen the sample
si%e increases:
!. ,he con"idence inter$al remains the same
. ,he con"idence inter$al e(pands becomes
7ider4
1. %he ,onfiden,e interval shrinks ("be,omes
narrower)
D. ,he standard de$iation o" (8bar increases
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POP QUIZ #2
-. In hypothesis testin0 the null hypothesis is
reEected 7hen:
!. P8$alue alpha
B. P$value # alpha
&. !lpha 5 critical $alueD. !lpha critical $alue
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POP QUIZ #+
1. ,he "itted reression line is typically
calculated by minimi%in the sum o":
!. ,he s
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POP QUIZ #+
2. In the "itted line e
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POP QUIZ #+
+. In the "itted line e
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POP QUIZ #+
/. @?* is used as an estimator "or:
!. ,he reression slope. ,he y8intercept
&. ,he mean o" the disturbance error4
D. %he varian,e of the disturban,e (error)*. ,he st. de$iation o" the disturbance error4
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POP QUIZ #+
-. !s part o" reression analysis0 7hy do 7e
7ant to test 7hether or not 1 3
!. It is the 7ay to see i" the y8intercept is %ero. It is the 7ay to see i" the assumptions hold
1. 5t is the way to see if 0 and 6 are linearly
related
D. It is the 7ay to see i" 6 is the only possible
predictor "or F
*. It is the 7ay to see i" the t distribution holds
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POP QUIZ #/
1. ,he relationship bet7een &O?, and
NU@POG,? is sini"icant i":
!. ,he G8s
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POP QUIZ #/
2. ased on the reression output belo70
Predictor Coef SE Coef T P
Constant 16594 2687 6.18 0.000
NUMPOTS 650.17 66.91 9.72 0.000
!. ,he constant is probably e
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POP QUIZ #/
+. ,estin the slope o" NU@POG,? "or
sini"icance0 the derees o" "reedom are:
A. n $ 3
. n 8 1
&. n
D. !l7ays e
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POP QUIZ #/
/. ! C- &.I. "or a reression slope is
al7ays:
!. ?ymmetrical around b3
B. +ymmetri,al around b!
&. &alculated usin the J distributionD. &alculated usin the % distribution
*. Non8symmetrical
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POP QUIZ #/
-. ,o test 7hether a relationship bet7een 6 and
F is positi$e0 7e need to test:
!. K3: 3 3 $s. Ka: 3 3. K3: 1 3 $s. Ka: 15 3
1. ;(< !" vs. ;a< !
D. K3: 1 3 $s. Ka: 1L 3*. K3: 3 3 $s. Ka: 3L 3
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POP QUIZ #-
1. Ge"errin to the !NOM! table0 ??, is
i$en as:
!. ??, ??G 8 ??*
. ??, ??G
&. ??, ??*D. ++% " ++: = ++4
*. ??, ??G ??*
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POP QUIZ #-
2. ,he &oe""icient o" Determination iscomputed as:
!. G ??G ??,
. G ??G ??*
1. :3
" ++: > ++%D. G2 ??, ??G
*. G2 ??, ??*
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POP QUIZ #-
+. ,he Geression J test is desined to e(amine:
A. Whether or not !"
. )hether or not 3 3
&. )hether or not 1 3 3
D. )hether or not 1 1
*. )hether or not 3 1
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POP QUIZ #-
/. In simple reression0 is it al7ays necessary
to conduct an J test
!. Fes0 the in"ormation pro$ided by an J test isuni
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POP QUIZ #-
-. Ge"er to the communication nodes e(ample. Is Nodes
a sini"icant predictor "or Cost !NOM! table i$en belo74
So!rce "# SS MS # P
e$ression 1 1751268%76 1751268%76 94.41 0.000esid!a& Error 12 222594146 18549512
Tota& 1% 197%862521
!. Fes0 because the J $alue is less than 3.3-
B. 6es/ be,ause the p value is less than .'&. No0 because the J $alue is $ery lare
D. No0 because the p $alue is $ery small
*. No0 because the J $alue is larer than the p $alue
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POP QUIZ #;
1. ,he reression model assumptions re"er to:
A. %he errors. ,he y8intercept
&. ,he slope coe""icients
D. !ll coe""icients0 includin y8intercept andslopes
*. ,he derees o" "reedom
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POP QUIZ #;
2. !nalysis o" @eddicorp ?ales produced the"itted line listed belo7. Ko7 do youinterpret the slope "or onus
S'(ES ) * 516 + 2.47 '", + 1.86 -ONUS
!. *ach 1 o" onus increases ?ales by 1.A;
B. 4a,h ?! of Bonus in,reases +ales by
?!/@/ if Adv is kept ,onstant
&. *ach 133 o" onus increases ?ales by 1A;
D. *ach 1 in ?ales increases onus by 1.A;
*. *ach 1.A; in ?ales increases onus by 1
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POP QUIZ #;
+. ased on the reression output belo70Predictor Coef SE Coef T P
Constant *516.4 189.9 *2.72 0.01%
'", 2.47%2 0.275% 8.98 0.000
-ONUS 1.8562 0.7157 2.59 0.017
!. Only !DM is a sini"icant predictor "or ?ales
. Only onus is a sini"icant predictor "or ?ales
1. Both AD and Bonus are signifi,ant predi,tors for +ales
D. Neither !DM nor onus are sini"icant predictors "or ?ales
*. ,he constant is neati$e0 there"ore there is an in$erse
relationship bet7een ?ales and !DM or onus
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POP QUIZ #;
/. ,he @ultiple Geression J test is desined to
e(amine:
!. )hether or not 1 3
. )hether or not 3 3
&. )hether or not 3 1 3
D. )hether or not 3 1 3
4. Whether or not !" 3" C "
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POP QUIZ #;
-. )hen you remo$e an e(planatory $ariable "rom a
reression model0
!. G2
7ill al7ays increase0 but G2
H adEusted may decreaseB. :3will always de,rease/ but :3 adEusted may in,rease
&. G27ill al7ays increase0 but G2H adEusted may or may not
increase
D. oth G 2and G2H adEusted 7ill al7ays increase*. oth G 2and G2H adEusted 7ill al7ays decrease