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**Unformatted text preview: **l . -4ruasf Statistics 217 NAME; ‘1‘ “ _
Quiz"? 4! 1. Which of the following pairs comply with the rules for setting up null & alternative hypotheses:
Ho: u= 15 X Ho: 1: 20.30 /
Ha: pi 15 Ha: 1r<0.80 0/
\l ' _ /0
/{ Ho: p = .35 /d./ Hypotheses from both a & b comply
Ha: p #3 .35 For items #2 & #3: Write out the appropriate null & alternative hypothesis for the speciﬁc research scenario. I 2. The mean length of time waiting on hold when calling the IRS during the month of April in 2005 was I’) h, . 25 minutes. In an effort to improve their image, in January of 2006 the IRS instituted a plan to reduce the a",
number of minutes people waited on hold. What hypothesis should the IRS test to determine whether the mean /\ 5%
number of minutes waited improved (was reduced)? \ ti 14,235 Wcuts'immmlé hcftirrtt
O warhn on hold when milliliﬁthtﬁﬁ
tin: MA 66 a \J 3. Teens comprise 14% of the driving population. Researchers studying 145 randomly selected auto
accidents found that 19% of accidents studied involved teen drivers. Does the data from this study provide convincing evidence that the proportion of accidents involving teen drivers differs from 0.14, the proportion of
teens in the driving population? tio‘lfiw wWQTCISW prupor FilOi i of
H61, '- Ttr. M MD 6‘00 darts Intel/Ingram drawn \/ \ é
- '\ 4 .A A A A i .. .. - ,
Statistics 217 (A) /0 NAME L . J Quiz 1, Fall 2006 1. The head of quality control at a printing company is interested in factors that affect the strength of the
binding on books that the company produces. She would like to carry out an experiment to determine
which of two different glues results in the greatest binding strength among 50 books (25 books for each
glue). Although not of interest in the current study, other factors thought to affect binding Strength
include number of pages in the book and whether the book is being bound as a paperback or hardback. What fa tor dete ines the pe mental condit on, and h w many 15631511063? have? \, . V .
b. What is the sample size in this study? W. What is the p0pu1ati0I1 in this Study? WWW d. Identify one extraneous variable n this s dy. State why t e v iabl is an extraneous vari ble 1n the 0" \f contextofthisstudy. 11‘ L7. 6; Q I.) I 1!. 'j‘_ ‘3 i- ' (I, L, i5
11’ ’1’; I Ill "VII .o‘u l 4 'QJIIII [’ I! “Hi I” ' mﬁmmi ' - became W61) .65 {EQUlmWe/W glue What is the classiﬁcation (e. g. categorical, etc.) f r the variable “Number of units enrolled in
for Fall quarter at Cal Poly”? i) 3. The graph below represents the distribution of annual salaries for 474 randomly selected employees of
a large corporation. 140 120 I 100 80
60
40 20 0 %%%%%%%%%%%%m \/ Current Salary a. What type of graph is this?
b. Provide an interpretation of the distribution for the annual salary variable (use co mlgplete sentence(s)): mdsrrihmw atannwlsalanesoreatesa r31 posrhlveltj
“stewed wrPn v iii/Wi’miis ftalsoi tdcmnupper mo, mm man 50161 «$10000 and +10. value calla WWWYIM
arﬂtaﬁmoo. 1mm pravalatt 541m} 15 amino! 315,000. W" Statistics 217-03, Quiz 2A NAME by. Z 2 value — mean where SD = standard deviation 1. Based on visual interpretation of the graphs below, match the correlations with the plots: //
O PIDIA Plot B PlDtC Plat D r= -0.77 _A _B _C AD
r= 0.46 _A _B 430 __D
= 0.85 _A AB _C _D
r= 1.00 iA ____B _C ___D \‘Q .\2\ Which of the following mean and median pairings best ﬁts a highly postively skewed distribution? a:'/ mean: 24, median: 24 k © //—\ mean= 24, median— — 4 —p,-—+—— ©\/ﬂ\
mean = 4, median = 24 q '3 5/ _ 7' +mrk “t— 1
. Impossible to answer without information for the mode ‘4 N,// M ”i
\8. What was in the Fed Ex package discussed during yesterday’s lecture: 3!]? Q,n%| I! ll l 2g
4. The ACT and SAT tests are designed to measure college preparedness. The distributions of scores for both these tests are normal. The mean ACT score is 20.3 with a standard deviation of 4.2. The mean
SAT score is 1618 with a standard deviation of 300. a. Jerry scored 28 6 on the ACT George scored 1,750 on the SAT. What is George’s
corresponding Z score for thg ‘? (Show your work)
m om : le 1%
SO 500
SQCX‘Q : 1 750 1760 — Ice? 8':
.,._m._.__. Obi
30C, b. What score on .he ACT corresponds to the 50lh percentile? 90 7D mini'rirwdim ...

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