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 Tuesday, October 13, 2009 Worthless statistics of the day Last Thursday I held my midterm exam in sports economics. Unfortunately, the exam format was multiple guess. Here is the tabulation of the answers:`. tab answer answer | Freq. Percent Cum.------------+----------------------------------- A | 15 30.00 30.00 B | 10 20.00 50.00 C | 12 24.00 74.00 D | 8 16.00 90.00 E | 5 10.00 100.00------------+----------------------------------- Total | 50 100.00`Why is this interesting? It isn't. However, some people might read into this and think - ah, if I don't know the answer then guess "A" because it is the most common answer. The mistake is thinking that I chose option "A" to be the most popular - I did not.Just because a distribution of a variable exists doesn't mean that it is useful for predictive purposes. Don't tell my undergraduate students.Labels: statistics posted at 10/13/2009 08:02:00 AM (2) comments Comments: Here's a slice of bologna: I'm guessing not all questions had an "E." what was the conditional probability (relative frequency) of the answer being "E" conditional on the fact that there was an "E" option? Just curious. # posted by  Bang : 1:34 PM   Good question. Eighteen of fifty questions had an "option E." Of those, five questions were answered correctly with "E". Thus, the conditional probability is 27%. If one had absolutely no clue between any of five possible answers, then choosing E would only slightly improve the odds of answering the question correctly. # posted by  Craig : 8:12 AM   Post a Comment Purchase Le Chai - galerie du vin Support Popularity Posts that contain Craig Depken per day for the last 90 days. Contacts Heavy Lifting's Main Page Email Me Atom Feed WWW Heavy Lifting Great Links Money I Found Today Heavy Lifting - Firehose style (56k warning) Recent Posts - Worthless statistics of the day Archives - Archives - 01/01/2004 - 02/01/2004 02/01/2004 - 03/01/2004 03/01/2004 - 04/01/2004 04/01/2004 - 05/01/2004 05/01/2004 - 06/01/2004 06/01/2004 - 07/01/2004 07/01/2004 - 08/01/2004 08/01/2004 - 09/01/2004 09/01/2004 - 10/01/2004 10/01/2004 - 11/01/2004 11/01/2004 - 12/01/2004 12/01/2004 - 01/01/2005 01/01/2005 - 02/01/2005 02/01/2005 - 03/01/2005 03/01/2005 - 04/01/2005 04/01/2005 - 05/01/2005 05/01/2005 - 06/01/2005 06/01/2005 - 07/01/2005 07/01/2005 - 08/01/2005 08/01/2005 - 09/01/2005 09/01/2005 - 10/01/2005 10/01/2005 - 11/01/2005 11/01/2005 - 12/01/2005 12/01/2005 - 01/01/2006 01/01/2006 - 02/01/2006 02/01/2006 - 03/01/2006 03/01/2006 - 04/01/2006 04/01/2006 - 05/01/2006 05/01/2006 - 06/01/2006 06/01/2006 - 07/01/2006 07/01/2006 - 08/01/2006 08/01/2006 - 09/01/2006 09/01/2006 - 10/01/2006 10/01/2006 - 11/01/2006 11/01/2006 - 12/01/2006 12/01/2006 - 01/01/2007 01/01/2007 - 02/01/2007 02/01/2007 - 03/01/2007 03/01/2007 - 04/01/2007 04/01/2007 - 05/01/2007 05/01/2007 - 06/01/2007 06/01/2007 - 07/01/2007 07/01/2007 - 08/01/2007 08/01/2007 - 09/01/2007 09/01/2007 - 10/01/2007 10/01/2007 - 11/01/2007 11/01/2007 - 12/01/2007 12/01/2007 - 01/01/2008 01/01/2008 - 02/01/2008 02/01/2008 - 03/01/2008 03/01/2008 - 04/01/2008 04/01/2008 - 05/01/2008 05/01/2008 - 06/01/2008 06/01/2008 - 07/01/2008 07/01/2008 - 08/01/2008 08/01/2008 - 09/01/2008 09/01/2008 - 10/01/2008 10/01/2008 - 11/01/2008 11/01/2008 - 12/01/2008 12/01/2008 - 01/01/2009 01/01/2009 - 02/01/2009 02/01/2009 - 03/01/2009 03/01/2009 - 04/01/2009 04/01/2009 - 05/01/2009 05/01/2009 - 06/01/2009 06/01/2009 - 07/01/2009 07/01/2009 - 08/01/2009 08/01/2009 - 09/01/2009 09/01/2009 - 10/01/2009 10/01/2009 - 11/01/2009 11/01/2009 - 12/01/2009 12/01/2009 - 01/01/2010 01/01/2010 - 02/01/2010 02/01/2010 - 03/01/2010 03/01/2010 - 04/01/2010 04/01/2010 - 05/01/2010 05/01/2010 - 06/01/2010 06/01/2010 - 07/01/2010 07/01/2010 - 08/01/2010 08/01/2010 - 09/01/2010 09/01/2010 - 10/01/2010 10/01/2010 - 11/01/2010 11/01/2010 - 12/01/2010 12/01/2010 - 01/01/2011 01/01/2011 - 02/01/2011 02/01/2011 - 03/01/2011 03/01/2011 - 04/01/2011 04/01/2011 - 05/01/2011 06/01/2011 - 07/01/2011 07/01/2011 - 08/01/2011 12/01/2011 - 01/01/2012 home Visitors Blogroll Me! Credits Modified maystar design powered by blogger