Math Is Fun Forum

finitehelp

Member

Registered: 2009-06-21

Posts: 80

Standard diviation problem

I read the chapter twice and all question on the test that went like the one below I failed. Where should I start?

Suppose it is observed that, on average, 35 people are admitted to the intensive care unit of a particular hospital every week. Let the random variable X represent the number of people admitted to this intensive care unit on any particular day.

a) What is the distribution of X?
b) What is the probability that the number of people admitted to this intensive care unit on a particular day is exactly 5?
c) What is the probability that the number of people admitted to this intensive care unit on a particular day is exactly 2?
d) What is the probability that the number of people admitted to this intensive care unit on a particular day is less than 2?

finitehelp

Member

Registered: 2009-06-21

Posts: 80

Re: Standard diviation problem

I know its a Poisson

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Standard diviation problem

Hi finitehelp;

Why do you think it is a Poisson process just because the guy on the other forum said so?

---

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.

anonimnystefy

Real Member

From: Harlan's World

Registered: 2011-05-23

Posts: 16,049

Re: Standard diviation problem

The other forum?

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“Here lies the reader who will never open this book. He is forever dead.
“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.

Bob

Administrator

Registered: 2010-06-20

Posts: 10,626

Re: Standard diviation problem

hi bobbym and anonimnystefy

Hope you are both well.

I thought it was Poisson.  Are you saying it isn't?

Bob

---

Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob

Bob

Administrator

Registered: 2010-06-20

Posts: 10,626

Re: Standard diviation problem

I believe this forum is the only universe there is. 

Don't blow up my brain by suggesting there are others. 

   

Bob

---

Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob

anonimnystefy

Real Member

From: Harlan's World

Registered: 2011-05-23

Posts: 16,049

Re: Standard diviation problem

Hi bob

Wish all the best to you and your family.

What I think bobbym wanted to say is that he needn't rush towards conclusions. Just because someone said it is Poisson doesn't mean our must be Poisson.

---

“Here lies the reader who will never open this book. He is forever dead.
“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Standard diviation problem

Hi Bob;

I am okay, hope you are well. I know that you have a sound reason for thinking that. I was just asking the OP if he had one. I came across his question on another forum while there and saw it partially answered. But that does not make it correct to blindly follow what someone else wrote.

---

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.

Bob

Administrator

Registered: 2010-06-20

Posts: 10,626

Re: Standard diviation problem

OK.  I'm with you on that.

Bob

---

Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob

finitehelp

Member

Registered: 2009-06-21

Posts: 80

Re: Standard diviation problem

I agree but my book tells me that. What I seek is a better understanding from someone who knows the material. When I get in front of that test the answer will have to come from within me. I mean no disrespect by posting in other forums. I simply see understanding.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Standard diviation problem

Hi finitehelp;

What is the name of the book you are talking about?

---

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.

finitehelp

Member

Registered: 2009-06-21

Posts: 80

Re: Standard diviation problem

my statistics book. i have read these 3 chapter multiple times. took the test failed and i dont want to fail the retest. my grade depends on it. for the last few years whenever i got stuck i come to the forums for help and i get nothing but help and positive energy. i was not trying to offend anyone by going on two forums

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Standard diviation problem

Forget about that, it is water under the bridge. I am not offended by it. What is the name and author of the book?

---

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.

finitehelp

Member

Registered: 2009-06-21

Posts: 80

Re: Standard diviation problem

Business statistics by black

finitehelp

Member

Registered: 2009-06-21

Posts: 80

Re: Standard diviation problem

........anyone interest in helping me out?

Bob

Administrator

Registered: 2010-06-20

Posts: 10,626

Re: Standard diviation problem

hi finitehelp,

It is a Poisson distribution question.

The mean = 5.    ( 35 in a week is 5 per day)

  In the formula it is written

and

so put x = 5 for the first answer.

Post it and I'll check your working.

Bob

---

Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Standard diviation problem

Hi;

anyone interest in helping me out?

Lots of people are, but the best person to help you out is you. Please try to do these by yourself. I have provided some of my answers, you can check to see if I did it right.

---

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.