End of preview
Unformatted text preview: iii/,x/ 1.13
Quiz 9.1A . AP Statistics Name: 1. For each of the following settings, define the parameter of interest and write the appropriate
null and alternative hypotheses for the test that is described.
f“:
(a) Thgean 3333333303 loaves of bread produced at the bakery where you work is supposed
to onapoundi You are the supervisor of quality control at the bakery, and you are
concerned that new personnel are producing loaves that have a mean weight of more than- one ound
p iiei- 3e l 3-; . QI {3.06.2- Hz" 3,3"; I
(b) According to the Humane Society®f households in the United States own at least
one cat. You are interested in determining whether the proportion of households of the ’
students at your school that own at least one cat is different from the national proportion. .. .1? P)“- Q ‘ .3..- 1),:
{EV H n J} H.) I332 pgfitr 833361;) '7 .
(:7; .3 .3 3:3“; ' Km 363"“ M33 (33 \312. :3 2.3.9;- . 2. Consider the bakery problem in question 1(a). Suppose you weigh an SRS of bread loaves
and find that the mean weight is 1.025 pounds, which yields a P-value of 0.086. M [email protected]‘Pivaluednrthecontext--o£the—problem._ 3:: Q I; II 33 ‘II 3.32 :2. II ‘32:: C:..I3I_ 33.320.3...6‘339113’3.’ 0.3 Q2:353:23 ' We. RM 3 '1‘; t2: I 3333c133 33. t3. (b) What conclusion would you draw at the CL = 0.05 level? At the on = 0.10 level? [Ail 73“ VG" Die “:5? (:5 _ 1;) figm- a) C} 8 Q!) {135‘ {:5
”2,3.ka U‘EDMKJ gig Qm1k§ 33:1 ”} Wk kliifisl 2!. (2.253 II») “*I\\(32\0\ J
\: ez‘skf‘gsw HJ222=I E: 333353“ - 3..
.9 PI Qm‘r‘I 3.33mi?) Q3333 1er I2: emit: Obxfij‘tltfi Ki. 33\ (:3. 2.33. Ilia. © 2011 BFW Publishers The Practice of Statistics, 4/e- Chapter’9 413 3 LI JVI IIIIII mash (”33.3303 I... Q33 333.43.333.23 Quiz 9.2A AP Statistics Name: ~ 1
E
E
i
f
E
’5
g
i 1.{ Elevenzgcent of the products produced by an industrial process over the past several
3‘ ' ave failed to conform to specifications. The company modifies the process in an attempt to reduce the rate of nonconformities. In a random sample oi 300 items from a trial
run, the modified process producess16 nonconforming item. Do these results provide convincing evidence that the modification is effective? Support your conclusion with a test :
of significance. :
H b t p a; . H l? t; "3% MIL @E at? bier-m 52%;) girlERlIWtMJQfi‘S‘gi‘zi‘i’fiflw3M
‘ i ‘ v *- I N t F
2‘" in A \‘ Pei . l \ _ ' EM? EM m Mfiibflm‘w :l C“ gal": 51-3523
(:9 .QWCLIn (gram , Q" I, _: w M . V ‘ .1? L3
#53 Jules n 650 ,,,,, l 6 (iii; mar ‘3 m“ t -‘ W. -
7 act-anon?) "é Kai’fig 33st “s32:- “WW"? “13 4““:
at
if
E; ”if
i :3 Am .- if? l! is} geifiifiQ/‘ifb‘é {34ch iatgiwx’} ED W>fl°¥fi G'lk '. _.»= i '2'
t‘ t. {V . t . rm 1).. ejs:..n.,,.,'§ri._,_i J"? (j M ' "\LT) © 2011 BFW Publishers The Practice of Statistics, 4/e- Chapter 9 419 i
g
i 2. The germination rate of seeds is defined as the proportion of seeds that, When properly '“x
planted and watered, sprout and grow. A certain variety of grass seed usually has a
germination rate of 0.80, and a company wants to see if spraying the seeds with a chemical
that is known to change germination rates in other species will change the gemiination rate of
this grass species. They spray 400 seeds with the chemical, and 307 of the seeds germinate.
This produces a 95% confidence interval for the proportion of seeds that germinate of (0.726,
0.809). ' " (a) Suppose the company conducted a test of H 0 : p = 0.8 against the alternative H a : p at 0.8, using 0L 3 0.05. Use the confidence interval to determine whether this test
would reject or fail to reject the null hypothesis. Explain your reasoning. ”(310343; a 2?}; gnlflefl Medellin-222%: Arie-wk {Eli‘wgl iimwgfi “minimal; iii; , {ENE-‘4? “a ”‘33“ PM“ WMQ’QB
. . . 2:3
{@223 “has misfit? Q5? 9%,me “‘Wgfiw hi3 VQQLLM 2a:
; A... by ‘ ‘ 7 a _ '7 3’ an.“
{2/ 8%.. a «a LA “$81653? Emlk/‘fitatflwil‘f Qufnfiisliwgug; X 2‘3 :3 S5
. WE“ T h k ' "Q ‘~ A. .i; l uifinflwfi- 3 , . l
' sat: sameness 613‘ “i it“: ‘1 8333‘ R58" Us allay-mfg 63’ a a“, | ‘m £44111}; fix . Ti
“if; “ 5th“: a Kid is; he‘ll/l m 3“ M3
$th spew} “2%) , W§3d§
‘u \hwzx ° (b) Find the P—Value for the test described in part (a). You do not need to present a complete “' 3
‘ significance test. Explain what the P—value measures in the context of the problem. i £5;ij “El. :2 angl- his? El ‘1’“ e f- m _ ”was: a; .2. l ., (356$: _ 4/” N‘s
- FET‘ - . W ' ' " t
. “in; , Pl‘lEif‘ “Wig—-
'2 (39* when ”-32 3’ of" Z“ 03% " 22K 7 . ail-AME
f \._ ‘35-: oqulkfit ' ‘le‘
C? ”W C ” 9‘78 WM finisher-it i843 EEOC; “time-2 A“ M {agent-1.2:: t- Carin 65W §\M,3;afi l “93% fl: £29m» ‘x. k , ‘ .‘ ' y A f I ‘ Quw
3;: 5:925:81? 93,: he QQJMWA main We {533% ‘32 ”E” “5% {IS-1133' :8; ‘ fig Qfiypmwfzuw hair? I}? ‘E {:3 Li I 3 420 3 The Practice of Statistics, 4/e— Chapter 9 © 2011 BFW Publishers 5
a
3
t
i
Z
3
E
i
E S» i
E
a
5
i
t3
.9 Quiz 9.3B AP Statistics 7 Name: 1. Sweet corn of a certain variety is known to produce individual ears of corn with a mean
weight of 8 ounces. A farmer is testing a new fertilizer designed to produce iarger ears of -
corn, as measured by their weight. He finds that 28 randomlyvselected ears of com grown
with this fertilizer have a mean weight of 8.25 ounces and a standard deviation of 0.8 ounces. There are no outliers in the data. (a) Do these samples provide convincing evidence at the on = 0.05 level that the feltilizer had
a positive impact on the weight of the corn ears? Justify your answer. ' cam: Cmfl‘gfl _ , . (53-99
“.Qomém‘“ 3W P“*m&\i;f:s Nscusmw Sum: 131130 7D . Narme-Q" W ffobfem 3*: .Qof & (gen SAMMQK‘O—Q \fxéQPQfiQQH
'3 Dotsfinw ” ”\WE’ when T30 “1013 % mm W (“h"- Xi
i
94
p
0" (“1‘
ii 31"”0‘? DEI/m
he. 1?
DP; 511 Vt VOA“; b OSqq 3
2
i
t (b) How would your conclusion change if your sample mean had been 8.26 ounces? What
point does this make about statistical significance?
\u us: an “re %3 QD‘LN'YS Sufi: AQAoJP JR MW (1.13% . K “g S\ «mm/m
Oc’ésmdthv ”the: Muck/x \ Nstwnge, +0 SM“??? 3
Show Us "some“ Chm-nah. uh. mun Cor QUL gmfiusiih . E
of?
a
it; © 2011 BFW Publishers The Practice of Statistics, tile- Chapter 9 427 i
t
i ...
View
Full Document