statistics folly

Michael Robinson · 2010-07-16T18:02:52+00:00

More options Jul 16, 1:24 pmNewsgroups: From: gearhead Date: Fri, 16 Jul 2010 10:24:41 -0700 (PDT)Local: Fri, Jul 16 2010 1:24 pmSubject: stats/probability questionReply | Reply to author | Forward | Print | Individual message | Showoriginal |Remove | Report this message | Find messages by this authorI'm an engineering undergrad in an intro stats course. We had aquestion in the book that's really dumb.problem as stated: Your candidate has 55% of the votes in the entire school. Butonly100 students will show up to vote. What is the probability that theunderdog (the one with 45% support) will win? To find out, set up asimulation.a) Describe how you will simulate a component and its outcomes.b) Describe how you will simulate a trial.c) Describe the response variable.The answer in the back of the book says using a two digit randomnumber to determine each vote (00-54 for your candidate, 55-99 for theunderdog) you would run a string of trials with 100 votes to eachtrial.Now, this is one misconceived exercise. Let me explain why.Say the school has 1000 students. If all of them show up, theunderdog has 0% chance of winning. If exactly one voter shows up,underdog has 45% chance of winning. In an election where 100 votersshow up, underdog's chance of winning the election HAS to liesomewhere between 0% and 45%. No ifs, ands or buts.The probability of a win for underdog can never exceed 45%. When theexercise asks "how often will the underdog win" I interpret that asmeaning what are his chances, i.e., the probability that he will win.But if you run a simulation, you can get anything, including resultsabove 45%. I don't think simulating has any validity here, at leastthe procedure suggested in the answer key. That is a lot ofsimulating to do by hand, 100 per trial, but it is nowhere close toeven starting to answer the actual question. You would first of allhave to know the population of the school and then do some verydemanding simulations that would only...

statistics folly

Jul 16, 2010 45 Replies

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JosephKK 16 years ago

Aw phooey. The student was supposed to bump their nose up against that, hard. It is one of those lessons that the only real way to learn it is to bump up aginst it the hard way.

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krw 16 years ago

exercise is

help them get

certainly

trying to

So you're better than AlwaysWrong. You've now said one correct thing in your life.

You're the clueless liar, Slowman.

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Richard Henry 16 years ago

The casino is Monte Carlo, which is a small part of the small country of Monaco.

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Richard Henry 16 years ago

ut,

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ess.

ve a

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her

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get

Got an F on the assignment?

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Joerg 15 years ago

Huh? Small? Monte Carlo and La Condamine are pretty much grown together. What's left is a little area called Fontvieille in the south and AFAIK there ain't much in the north. And that's pretty much it.

Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.

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Richard Henry 15 years ago

ots

for

ccording to the CIA World Factbook

formatting link

Monaco contains only one city, named Monaco, which encompasses all the area of the country. Monte Carlo is an administrative division (quartier) of that city/country.

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