Math Is Fun Forum

basketboy

Member

Registered: 2011-10-11

Posts: 14

cant solve

if the joint probability distrubution of x and y is given by

f(x,y)=x+y/3,for x=0,1,2,3  y=0,1,2 find

p(x<2,y=1)
p(x>2,y<1)
p(x>y)
p(x+y=4)

Bob

Administrator

Registered: 2010-06-20

Posts: 10,583

Re: cant solve

hi basketboy

That's better.

I've assumed you meant

not

NEW TABLE FOR CHANGED pdf

Have a look at the table at the bottom of this post.

It shows the 12 possible outcomes.

AND IT IS A PDF. THE FRACTIONS ADD UP TO 30/30 = 1

P(x<2 and y = 1) means (x=0,y=1) and (x=1,y=1)

The probabilities for these are 1/30 and 2/30 so the probability is 3/30 = 1/10

THIS IS NOT THE ANSWER I GAVE THIS MORNING WITH DIFFERENT pdf.

Use the table and try the other questions.  Post your answers and I'll check them.

Bob

Last edited by Bob (2011-10-12 04:48:56)

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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: cant solve

Hi basketboy;

One post per question please. If you post in "Help me' you will get help. Please do not post multiple times.

---

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: 10,583

Re: cant solve

hi bobbym

How are you today?

I think he knows that now.  It was just inexperience.

He posted in the other thread and I asked him to re-post as a new topic.  Ie.  Here.  I've taken out my posts from the other thread so it's just his original post there that needs to be deleted.  Hence my comment above.  He can do it when he logs back in;  but can you?

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: cant solve

Hi;

I am fine, how are you?

I took care of it. All the other threads have been deleted. You can remove your link.

---

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: 10,583

Re: cant solve

Hi bobbym,

I'm fine too.  We are planning some new building work on our house, so I'm trying to get a decent 3D for my neighbour using Google sketchup.  Considering that it's free it does a fairly decent job, but sometimes it 'makes assumptions' about what I'm trying to draw that then take half an hour to put right.  Arrhhh, computers, don't you just love them?

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: cant solve

Hi;

They are a pain. If only they were slightly smarter then they would be offended by all the swearing at them.

---

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: 10,583

Re: cant solve

Ha ha!

---

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