DSCI5180 Spring2013 Quizzes1-6

8/9/2019 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


2/31

2

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


3/31

+

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


4/31

/

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


5/31

-

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.-


6/31

;

POP QUIZ #1

-. ,he probability that a consumer


7/31

>

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


8/31

A

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


9/31

C

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


10/31

13

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


11/31

11

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


12/31

12

POP QUIZ #+

1. ,he "itted reression line is typically

calculated by minimi%in the sum o":

!. ,he s


13/31

1+

POP QUIZ #+

2. In the "itted line e


14/31

1/

POP QUIZ #+

+. In the "itted line e


15/31

1-

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


16/31

1;

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


17/31

1>

POP QUIZ #/

1. ,he relationship bet7een &O?, and

NU@POG,? is sini"icant i":

!. ,he G8s


18/31

1A

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


19/31

1C

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


20/31

23

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


21/31

21

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


22/31

22

POP QUIZ #-

1. Ge"errin to the !NOM! table0 ??, is

i$en as:

!. ??, ??G 8 ??*

. ??, ??G

&. ??, ??*D. ++% " ++: = ++4

*. ??, ??G ??*


23/31

2+

POP QUIZ #-

2. ,he &oe""icient o" Determination iscomputed as:

!. G ??G ??,

. G ??G ??*

1. :3

" ++: > ++%D. G2 ??, ??G

*. G2 ??, ??*


24/31

2/

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


25/31

2-

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


26/31

2;

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


27/31

2>

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


28/31

2A

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


29/31

2C

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


30/31

+3

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 "


31/31

+1

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

DSCI5180 Spring2013 Quizzes1-6

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