[npl] / trunk / NationalProblemLibrary / UVA-Stat / setStat212-Homework11 / stat212-HW11-20.pg Repository: Repository Listing bbplugincoursesdistsnplrochestersystemwww

# View of /trunk/NationalProblemLibrary/UVA-Stat/setStat212-Homework11/stat212-HW11-20.pg

Revision 454 - (download) (annotate)
Thu Jul 5 18:11:13 2007 UTC (5 years, 10 months ago) by jjholt
File size: 3127 byte(s)
Consolidated tags.


    1 ##DESCRIPTION
2 ##KEYWORDS('statistics','Inference about a population')
3 ##
4 ## CMMK tagged this problem
5
6 ## DBchapter('Inference About a Population')
7 ## DBsection()
8 ## Date('07/12/2005')
9 ## Author('Cristina Murray-Krezan')
10 ## Institution('UVa')
11 ## TitleText1('Statistics for Management and Economics')
12 ## EditionText1('6')
13 ## AuthorText1('Keller, Warrack')
14 ## Section1()
15 ## Problem1()
16
17
18 ##ENDDESCRIPTION
19
20 DOCUMENT();        # This should be the first executable line in the problem.
21
22 loadMacros(
23 "PG.pl",
24 "PGbasicmacros.pl",
25 "PGchoicemacros.pl",
26 "PGanswermacros.pl",
27 "PGnumericalmacros.pl",
28 "PGstatisticsmacros.pl",
29 "PGauxiliaryFunctions.pl",
30 "extraAnswerEvaluators.pl"
31 );
32
33
34 TEXT(beginproblem());
35 $showPartialCorrectAnswers = 1; 36 # install_problem_grader(~~&std_problem_grader); 37 38$pval = 0;
39 while ($pval < 0.003) { 40 41$n1 = random(80,100,1);
42 $n2 = random(80,100,1); 43$x1 = $n1 - random(25,35); 44$x2 = $n2 - random(40,50); 45 46$phat1 = $x1/$n1;
47 $phat2 =$x2/$n2; 48 49$alpha = random(0.01,0.10,0.001);
50
51 $zcrit = udistr($alpha);
52 $se = sqrt($phat1*(1-$phat1)/$n1 + $phat2*(1-$phat2)/$n2 ); 53$zstat = (($phat1-$phat2)-.05)/$se; 54$pval = uprob($zstat); 55 } 56 57$mc = new_multiple_choice();
58
59 @ans = ("Reject $$H_0$$.", "Do Not Reject $$H_0$$.",
60         "Reject $$H_1$$.", "Do Not Reject $$H_1$$.");
61
62 if ($pval <$alpha) {$tag = 0;} else {$tag = 1;}
63
64 $mc -> qa('D. Your decision for the hypothesis test:',$ans[$tag]); 65 66$mc -> extra($ans[1-$tag],$ans[2],$ans[3]);
67
68 BEGIN_TEXT
69 $PAR 70 A marketing research firm suspects that a particular product 71 has higher name recognition among college graduates than among 72 high school graduates. A sample from each population is selected, 73 and each asked if they have heard of the product in question. 74 A summary of the sample sizes and number of each group 75 answering yes'' are given below: 76$PAR
77 $78 \begin{array}{lll} 79 \mbox{College Grads (Pop. 1)}: & n_1 = n1, & x_1 = x1 \\ 80 \mbox{High School Grads (Pop. 2)}: & n_2 = n2, & x_2 = x2 \\ 81 \end{array} 82$
83 $PAR 84 The company making the product is willing to increase marketing 85 targeted at high school graduates if the difference between the 86 two groups is at least 5$PERCENT.
87 Is there evidence, at an $$\alpha = alpha$$ level of significance,
88 to support such an increase in marketing?
89 Carry out an appropriate
90 hypothesis test, filling in the information requested.
91 $PAR 92 93 A. The value of the standardized test statistic: \{ ans_rule(25) \} 94$PAR
95 $BBOLD Note:$EBOLD For the next part, your answer should use interval notation.  An
96 answer of the form $$(-\infty, a)$$ is expressed (-infty, a), an answer of the
97 form $$(b, \infty)$$ is expressed (b, infty), and an answer of the
98 form $$(-\infty, a) \cup (b, \infty)$$ is expressed (-infty, a)U(b, infty).
99 $PAR 100 B. The rejection region for the standardized test statistic: \{ ans_rule(25) \}$PAR
101 $PAR 102 C. The p-value is \{ ans_rule(25) \}$PAR
103
104 \{ $mc ->print_q() \}$BR
105 \{ $mc ->print_a() \} 106 107 END_TEXT 108 109 ANS(num_cmp($zstat));
110 ANS(interval_cmp("($zcrit,infty)", sloppy=>'yes')); 111 ANS(num_cmp($pval,tol=>0.005));
112 ANS(radio_cmp(\$mc->correct_ans));
113
114 ENDDOCUMENT();       # This should be the last executable line in the problem.


 aubreyja at gmail dot com ViewVC Help Powered by ViewVC 1.0.9