Bike Forums > Foo > Not sure what this statistics question is asking
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 Foo Off-Topic chit chat with no general subject.

 02-02-09, 10:29 PM #1 phantomcow2 la vache fantôme Thread Starter     Join Date: Aug 2004 Location: NH Bikes: Posts: 6,266 Mentioned: 0 Post(s) Tagged: 0 Thread(s) Quoted: 1 Post(s) Not sure what this statistics question is asking A homework problem from my textbook: A financial analyst was asked to evaluate earnings prospects for seven corporations over the next year and to rank them in order of predicted growth rates. How many different rankings are possible? I know that the answer is 5040. How does this make sense? When they say "over the next year," is the analyst recording daily activity? Can somebody provide some insight here? __________________ C://dos C://dos.run run.dos.run
 02-02-09, 10:36 PM #2 alpacalypse Senior Member   Join Date: Jan 2008 Bikes: Posts: 284 Mentioned: 0 Post(s) Tagged: 0 Thread(s) Quoted: 0 Post(s) It's a permutation problem. You have 7 items, and the question is asking how many different ways they can be ordered. The number of possible permutations (orderings) is the factorial of the number of items: 7! = 7 * 6 * 5 * 4 * 3 * 2 * 1 = 5040.
 02-02-09, 10:43 PM #3 phantomcow2 la vache fantôme Thread Starter     Join Date: Aug 2004 Location: NH Bikes: Posts: 6,266 Mentioned: 0 Post(s) Tagged: 0 Thread(s) Quoted: 1 Post(s) I see that it is a permutations problem now. What I don't fully understand is what exactly is being ordered? __________________ C://dos C://dos.run run.dos.run
 02-02-09, 10:53 PM #4 valygrl Senior Member   Join Date: Jul 2003 Location: Boulder, CO Bikes: Posts: 8,546 Mentioned: 82 Post(s) Tagged: 0 Thread(s) Quoted: 162 Post(s) It's irrelevant what is being ordered or how the values are assigned. The question is just asking how many ways they can be ranked.
 02-02-09, 11:03 PM #5 phantomcow2 la vache fantôme Thread Starter     Join Date: Aug 2004 Location: NH Bikes: Posts: 6,266 Mentioned: 0 Post(s) Tagged: 0 Thread(s) Quoted: 1 Post(s) Brain fart :/ I feel like I am unable to comprehend statistics problems right now. __________________ C://dos C://dos.run run.dos.run
 02-02-09, 11:09 PM #6 FlowerBlossom My tank takes chocolate.     Join Date: Jun 2005 Location: Olympia, WA Bikes: Trek 600 series touring bike, Trek 800 hybrid, Bianchi Posts: 6,344 Mentioned: 0 Post(s) Tagged: 0 Thread(s) Quoted: 0 Post(s) This isn't statistics. Does that make you feel better? But, you need these kinds of processes to understand populations, which is what statistics is about. __________________ Feminism is the profound notion that women are human beings.
 02-02-09, 11:10 PM #7 alpacalypse Senior Member   Join Date: Jan 2008 Bikes: Posts: 284 Mentioned: 0 Post(s) Tagged: 0 Thread(s) Quoted: 0 Post(s) The companies' projected growths are being ordered, but that doesn't matter for the question-- it's just asking how many different ways they could be ordered.