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#1 2011-04-19 15:49:46
- blurguy
- Member
- Registered: 2011-04-19
- Posts: 35
demands?
on average, the demands for a particular electronic device at a warehouse are made 4 times
a) not demanded at all on a given day
b) demanded at least 5 times during 2 days
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#2 2011-04-19 16:04:54
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: demands?
Hi;
Should there not be a little bit more to this question?
I guess he is gone. It looks like he wants the probability, for that you use a poisson distribution.
a) P(0 in a day) = .0183
b) P(at least 5 in 2 days) = .9003
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
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#3 2011-04-19 18:48:55
- blurguy
- Member
- Registered: 2011-04-19
- Posts: 35
Re: demands?
yeh bobbym
actualy i dont no how to use any formula that should be right to question
"poisson distribution"
thanks about info....
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#4 2011-04-19 18:50:41
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: demands?
You can use this online calculator.
http://stattrek.com/Tables/Poisson.aspx#examples
Are you saying you do not know how to do these?
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
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#5 2011-04-19 19:11:27
- blurguy
- Member
- Registered: 2011-04-19
- Posts: 35
Re: demands?
yes! I wanted know this so thank you
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#6 2011-04-19 19:20:21
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: demands?
For a)
The poisson distribution uses this formula
Where x is the expected value in this case 4 ( the average )
k is the number of occurrences you want.
So you get;
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
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#7 2011-04-19 19:50:30
- blurguy
- Member
- Registered: 2011-04-19
- Posts: 35
Re: demands?
ok thank you bobbym
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#8 2011-04-19 20:05:59
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: demands?
For b)
This one is a little tougher:
k= 5,6,7,8,9...
x = 8 because that is the expected number for 2 days. ( 4 per day )
You only have to go to k = 22 to get 4 digits of accuracy. A faster way is to use the binomial distribution to estimate this answer. But I do not remember how...
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
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#9 2011-04-19 20:19:53
- blurguy
- Member
- Registered: 2011-04-19
- Posts: 35
Re: demands?
fuh! long question ....
how do I answer my final exam later on 24 / 4
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#10 2011-04-19 21:04:05
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: demands?
Hi;
You can use this calculator right here for b).
http://stattrek.com/Tables/Poisson.aspx#examples
The CDF of the Poisson distribution is not easy to calculate so if they ask a question like that they will give you a chart.
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
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#11 2011-04-19 22:35:13
- blurguy
- Member
- Registered: 2011-04-19
- Posts: 35
Re: demands?
http://stattrek.com/Tables/Poisson.aspx#examples
this want easy for culculate right 
thanks bro....
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#12 2011-04-19 23:17:07
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: demands?
If they give you a question like that they ought to provide a chart or a table to do it.
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
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#13 2011-04-20 02:28:07
- blurguy
- Member
- Registered: 2011-04-19
- Posts: 35
Re: demands?
ok thanks...
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#14 2011-04-20 11:25:18
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: demands?
Hi blurguy;
Your welcome. Are we all done here?
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
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