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1 : jjholt 451 ## DESCRIPTION
2 :     ## Statistics: Continuous Probability Distributions
3 :     ## ENDDESCRIPTION
4 :    
5 :     ## KEYWORDS('statistics', 'continuous probability distributions', 'probability distributions')
6 :     ## CMMK tagged this problem.
7 :    
8 :     ## DBchapter('What is Statistics?')
9 :     ## DBsection()
10 :     ## Date('6/17/2005')
11 :     ## Author('Cristina Murray-Krezan')
12 :     ## Institution('UVA')
13 :     ## TitleText1('Statistics for Management and Economics')
14 :     ## EditionText1('6')
15 :     ## AuthorText1('Keller, Warrack')
16 :     ## Section1()
17 :     ## Problem1()
18 :    
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 :     );
31 :    
32 :     TEXT(beginproblem());
33 :     $showPartialCorrectAnswers = 0;
34 :     install_problem_grader(~~&std_problem_grader);
35 :    
36 :     $mc[1] = new_multiple_choice();
37 :     $mc[1]->qa('The finite population correction factor should not be used when:',
38 :     'we are sampling from an infinite population'
39 :     );
40 :     $mc[1]->extra(
41 :     'we are sampling from a finite population',
42 :     'sample size is greater than 1$PERCENT of the population size',
43 :     );
44 :    
45 :     $mc[1]->makeLast(
46 :     'None of the above statements is correct'
47 :     );
48 :    
49 :    
50 :     $mc[2] = new_multiple_choice();
51 :     $mc[2]->qa('If two populations are normally distributed, the
52 :     sampling distribution of the sample mean difference \(\bar{X_1}-\bar{X_2}\) will be:',
53 :     'normally distributed'
54 :     );
55 :     $mc[2]->extra(
56 :     'approximately normally distributed',
57 :     'normally distributed only if both sample sizes are greater than 30',
58 :     'normally distributed only if both population sizes are greater than 30'
59 :     );
60 :    
61 :    
62 :     $mc[3] = new_multiple_choice();
63 :     $mc[3]->qa('Given a binomial distribution with \(n\) trials and
64 :     probability \(p\) of success on any trial, a conventional rule
65 :     of thumb is that the normal distribution will provide an adequate
66 :     approximation of the binomial distribution if',
67 :     '\(np \geq 5\) and \(n(1-p) \geq 5\)'
68 :     );
69 :     $mc[3]->extra(
70 :     '\(np \leq 5\) and \(n(1-p) \leq 5\)',
71 :     '\(np \geq 5\) and \(n(1-p) \leq 5\)',
72 :     '\(np \leq 5\) and \(n(1-p) \geq 5\)'
73 :     );
74 :    
75 :    
76 :     $mc[4] = new_multiple_choice();
77 :     $mc[4]->qa('If two random samples of sizes \(n_1\) and \(n_2\) are
78 :     selected independently from two populations with means \(\mu_1\)
79 :     and \(\mu_2\), then the mean of the sampling distribution of the
80 :     sample mean difference, \(\bar{X_1}-\bar{X_2}\), equals',
81 :     '\(\mu_1 - \mu_2\)'
82 :     );
83 :     $mc[4]->extra(
84 :     '\(\mu_1 + \mu_2\)',
85 :     '\(\mu_1 / \mu_2\)',
86 :     '\(\mu_1\mu_2\)'
87 :     );
88 :    
89 :    
90 :     $mc[5] = new_multiple_choice();
91 :     $mc[5]->qa('If two random samples of sizes \(n_1\) and \(n_2\) are
92 :     selected independently from two populations with variances \(\sigma_1^2\)
93 :     and \(\sigma_2^2\), then the standard error of the sampling distribution
94 :     of the sample mean difference, \(\bar{X_1}-\bar{X_2}\), equals',
95 :     '\(\displaystyle \sqrt{\frac{\sigma_1^2}{n_1}+\frac{\sigma_2^2}{n_2}}\)'
96 :     );
97 :     $mc[5]->extra(
98 :     '\(\displaystyle \sqrt{\frac{\sigma_1^2 - \sigma_2^2}{n_1 n_2}}\)',
99 :     '\(\displaystyle \sqrt{\frac{\sigma_1^2 + \sigma_2^2}{n_1 n_2}}\)',
100 :     '\(\displaystyle \sqrt{\frac{\sigma_1^2}{n_1}-\frac{\sigma_2^2}{n_2}}\)'
101 :     );
102 :    
103 :    
104 :     $a = random(1,5,1);
105 :     $b = random(1,5,1);
106 :     while ($a==$b){
107 :     $b=random(1,5,1);
108 :     }
109 :    
110 :    
111 :     BEGIN_TEXT
112 :     $PAR
113 :     \{ $mc[$a]->print_q() \}
114 :    
115 :     \{ $mc[$a]->print_a() \}
116 :     $PAR
117 :     \{ $mc[$b]->print_q() \}
118 :    
119 :     \{ $mc[$b]->print_a() \}
120 :     $PAR
121 :    
122 :     END_TEXT
123 :    
124 :     ANS(radio_cmp($mc[$a]->correct_ans));
125 :     ANS(radio_cmp($mc[$b]->correct_ans));
126 :    
127 :     ENDDOCUMENT(); # This should be the last executable line in the problem.

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