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.

Question

pink.1d · Answer

This is my graph

pink.1d · Answer

table***

pink.1d · Answer

Use social media regularly   	Don't use social media
Younger than 18	              16	                                        4
Older than 18	                       11                                         	9

pink.1d · Answer

@perl

pink.1d · Answer

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

pink.1d · Answer

@dan815 @iambatman @triciaal

perl · Answer

lets start with the first question

pink.1d · Answer

okay:)

perl · Answer

first find the totals http://prntscr.com/7cj8yl

perl · Answer

Let A =  Use social media regularly 
Let B = Younger than 18

P( A | B) = 16/20
P(B|A) = 16/27

pink.1d · Answer

i understand up to now

pink.1d · Answer

i dont get what they mean when it says ' Explain what each probability means in the context of the situation and data you collected.' i dont know how to answer that. i know how to find the answer but i m not sure how to answer that

perl · Answer

P(A | B) means probability use social media regularly given that we only look at people who are younger than 18 http://prntscr.com/7cja04 Or another way to say it, of people who are younger than 18 what is probability that randomly selecting one uses social media

perl · Answer

so we only look at that top row

pink.1d · Answer

so the top row and 1s2 colum?

pink.1d · Answer

1st*

pink.1d · Answer

younger than 18 and use social media

pink.1d · Answer

@perl @perl @perl @perl dont leave

pink.1d · Answer

YAY ur back! :)

perl · Answer

right, top row and first colmun is P(A|B)

perl · Answer

P(A|B) corresponds to top row and first colmun 
also we can express it as 
P(A|B) =P(A∩B) / P(B)

pink.1d · Answer

what does p(b line a) mean. it means

perl · Answer

P(B|A) says to look in only first column, first row

pink.1d · Answer

so what exactly does that mean?

pink.1d · Answer

im confused

pink.1d · Answer

does it mean it all out of total

perl · Answer

If we define http://prntscr.com/7cjcnn P(B|A) says to look in only first column A P(A|B) says to look only in first row B

pink.1d · Answer

can you look over the answer I wrote?

perl · Answer

what did you write

pink.1d · Answer

P(B | A) means probability of those under 18 who use social media regularly out of the total people that use social media regularly

pink.1d · Answer

P(A | B) : This probability means  means probability of those under 18 who use social media regularly out of all the people under 18

perl · Answer

do you agre that I defined A = "those who use social media regularly"

pink.1d · Answer

am i right?

perl · Answer

agree*

pink.1d · Answer

or wrong

perl · Answer

its kind of hard to say, its a bit confusing what you wrote for the second one

pink.1d · Answer

P(A | B) : This means probability of those under 18 who use social media regularly out of all the people under 18

pink.1d · Answer

i edited that

pink.1d · Answer

is the first one right?

pink.1d · Answer

@perl

perl · Answer

P(A|B): probability that a person who is younger than 18 uses social media regularly.

perl · Answer

P(B|A): Probability that a person who uses social media regularly is younger than 18.

perl · Answer

http://prntscr.com/7cjfig

pink.1d · Answer

@perl can you help me with the second one please?

pink.1d · Answer

NEVERMIND

pink.1d · Answer

THANKS FOR ALL THE HELP