- #1

fiksx

- 77

- 1

- Homework Statement
- probability three event

- Relevant Equations
- i could find ##P(T \cup F) = P(T)+P(F)-P(T \cap F)=55\% +53\%-20\%=88% ## is this right?

##P(T) =35## but i dont know ##P(T \cap I)##

A questionnaire survey on the use of SNS was conducted for students at A University. As a result,

we got the following:

##55\%## using Twitter ,

##53\%## using Facebook ,

##20\%## using Twitter and facebook both,

##19\%## use both Facebook and

Instagram.

##76\%## use at least Twitter

and / or Instagram

##72\%## use at least one of Facebook

and Instagram

##49\%## use only one of twitter ,facebook, or instagram

At this time, find the next

ratio respectively.

##1##. Percentage of using both

Twitter and Instagram

##2##. Percentage of using all

of Twitter, Facebook and Instagram

##3##. Percentage of not using

either Twitter, Facebook or Instagram

I was confused, for ##P(T\cap F)=20\%## does this also include ##P(T\cap F \cap I )## ?

for ##P(F) ## pnly ##P(F\cap T)##, is it correct only facebook is ##14\%##?

##P(F)=53\% - P(F\cap T) - P(F\cap I)=53\%-19\%-20\% =14\%##?i could find ##P(T \cup F) = P(T)+P(F)-P(T \cap F)=55\% +53\%-20\%=88% ##

is this right?

##P(T) =35##

but i don't know

##P(T \cap I)##

P(F)=14

i manage to find :

##P(T \cap I) = 17## and ##P(I)=38##

but when i count

##P(T \cup F \cup I) = P(T)+P(F)+P(I)-P(T \cap F) - P(T \cap I) - Ｐ(I \cap F) + P(T \cap F \cap I) = ##

##49=55+53+38-20-19-17 +P(T \cap F \cap I) ##

##P(T \cap F \cap I)=-41##

we got the following:

##55\%## using Twitter ,

##53\%## using Facebook ,

##20\%## using Twitter and facebook both,

##19\%## use both Facebook and

Instagram.

##76\%## use at least Twitter

and / or Instagram

##72\%## use at least one of Facebook

and Instagram

##49\%## use only one of twitter ,facebook, or instagram

At this time, find the next

ratio respectively.

##1##. Percentage of using both

Twitter and Instagram

##2##. Percentage of using all

of Twitter, Facebook and Instagram

##3##. Percentage of not using

either Twitter, Facebook or Instagram

I was confused, for ##P(T\cap F)=20\%## does this also include ##P(T\cap F \cap I )## ?

for ##P(F) ## pnly ##P(F\cap T)##, is it correct only facebook is ##14\%##?

##P(F)=53\% - P(F\cap T) - P(F\cap I)=53\%-19\%-20\% =14\%##?i could find ##P(T \cup F) = P(T)+P(F)-P(T \cap F)=55\% +53\%-20\%=88% ##

is this right?

##P(T) =35##

but i don't know

##P(T \cap I)##

P(F)=14

i manage to find :

##P(T \cap I) = 17## and ##P(I)=38##

but when i count

##P(T \cup F \cup I) = P(T)+P(F)+P(I)-P(T \cap F) - P(T \cap I) - Ｐ(I \cap F) + P(T \cap F \cap I) = ##

##49=55+53+38-20-19-17 +P(T \cap F \cap I) ##

##P(T \cap F \cap I)=-41##