Question

Help with probability?

Answer 1

@uri @perl @ganeshie8

Answer 2

I will help :) What's the problem

Answer 3

Choose a row and column and compare P(A | B) with P(B | A). Explain what each probability means in the context of the situation and data you collected.:

Answer 4

Alright do you know how to find the probability of this? Or is that what you need help with?

Answer 5

I'm just kinda lost on what column to choose.

Answer 6

And where to go from there.

Answer 7

Choose any one

Answer 8

Okay, how about Nikon professional photographers to Canon professional photographers?

Answer 9

@undeadknight26

Answer 10

One second please :)

Answer 11

Okay, sorry!

Answer 12

It's fine m8 :)

Answer 13

I'm just refreshing my memory on probability lol

Answer 14

Well you chose the Professional column right?

Answer 15

Yes!

Answer 16

This question is busting my brain ._.
@acxbox22 @surjithayer @sleepyjess @dan815 @geny55 @gabylovesu @campbell_st @Nurali @robtobey

Answer 17

Sorry mate I thought I could do it but I forgot everything about probability :/

Answer 18

Would you like help with this?

Answer 19

Yes please!

Answer 20

you want to compare P(A|B) and P(B|A)
First lets define A and B

Answer 21

Okay, how?

Answer 22

Let
A = professional
B = Nikon brand

Once you define A and B, then it forces the complements to be:
A' = non professional
B' = the other brand Canon

Answer 23

Okay got it. So how would I label that with P(A | B) and P(B | A)?

Answer 24

P(A|B) means the probability of event A given that you know event B has already occured. On the table this means we only look at event B's row or column

Answer 25

Okay, so P(8|12)?

Answer 26

P( A|B) = P( professional | Nikon brand )

Answer 27

Oh so I don't need to put any numbers in?

Answer 28

The given part means that we only look in the row 'Nikon'

Answer 29

Oh okay! So P(Profesional | Nikon) and P(Nikon | Profesional)?

Answer 30

Professional*

Answer 31

P( A|B) = P( professional | Nikon brand )
we look only in the Nikon row. http://prntscr.com/7kwtse
therefore P(A|B) = 8/10

Answer 32

the `|` symbol means 'given' .

Answer 33

OHH I understand!

Answer 34

And then vise versa for P(B | A)?

Answer 35

yes

Answer 36

Okay, what about P(A∩B) with P(A∪B)?

Answer 37

P( B|A) = P( Nikon brand | Professional )
http://prntscr.com/7kwury
8/12

Answer 38

Got it! What about my question above?

Answer 39

Okay, what about P(A∩B) = 8/20
P(A∪B) = (8 + 2 + 4) / 20

Answer 40

That's it?

Answer 41

little more detail here

Answer 42

P(A∩B) : probability of professional `and` Nikon
http://prntscr.com/7kwx9w

= 8/20

P(A∪B) : probiablity of professional `or` Nikon
http://prntscr.com/7kwxo7

= (8 + 2 + 4) / 20

Answer 43

You can think think of it in terms of intersection of row and column
P(A∩B) http://prntscr.com/7kx0gv

Answer 44

Ohh okay! So I said...

Compare P(A∩B) with P(A∪B), and explain what each probability means in the context of the situation and data you collected.:

P(A∩B) = 8/20 (probability of professional and Nikon). Here, were only looking at the eight professional Nikon photographers. P(A∪B) = (8 + 2 + 4) / 20 (probability of professional or Nikon). Here, we’re using data from the professional column of Canon and Nikon plus Nikon’s two non-professionals.

Answer 45

Looks good :)

Answer 46

Okay great! Thank you so much! Only three more homework assignments till I graduate!

Answer 47

A∩B is also called `A intersect B` or `A & B `
A∪B is called `A union B` or `A or B `

Answer 48

Good luck :)

Answer 49

Alright, it's in my notes now. Thank you!