View of /trunk/rochester_problib/setProbability4Conditional/ur_pb_4_1.pg

    1 ##DESCRIPTION
    2 ##KEYWORDS('probability','events','conditional')
    3 ##
    4 ##ENDDESCRIPTION
    5 
    6 DOCUMENT();        # This should be the first executable line in the problem.
    7 
    8 loadMacros(
    9 "PG.pl",
   10 "PGbasicmacros.pl",
   11 "PGchoicemacros.pl",
   12 "PGanswermacros.pl",
   13 "PGgraphmacros.pl",
   14 "PGauxiliaryFunctions.pl"
   15 );
   16 
   17 TEXT(&beginproblem);
   18 $showPartialCorrectAnswers = 1;
   19 
   20 $a = random(0.2,0.5,0.1);
   21 $b = random(0.6,0.9,0.1);
   22 $d = 0;
   23 if ($a + $b > 1 ) {$d = $a + $b -1;}
   24 $c = random($d,$a,0.05);
   25 $ans1 = $c / $b;
   26 $ans2 = $c / $a;
   27 
   28 BEGIN_TEXT
   29 $BR
   30 If \( P(A) = $a \), \( \ P(B) = $b \), \ and \( \ P(A \cap B) = $c \), \ then $BR
   31 (a) \( \) \( P(A|B) = \)\{ans_rule(10)\} \ and $BR
   32 (b) \( \) \( P(B|A) = \)\{ans_rule(10)\}
   33 
   34 END_TEXT
   35 
   36 &ANS(arith_num_cmp($ans1));
   37 &ANS(arith_num_cmp($ans2));
   38 
   39 
   40 ENDDOCUMENT();       # This should be the last executable line in the problem.
   41