Question

According to the Pew Internet & American Life Project, 54% of Internet users have a wireless connection to the Internet via a laptop, cell phone, game console, or other mobile device. Given that users have a wireless, 25% use Twitter to share updates about themselves. What is the probability that an Internet user has a wireless connection and also uses Twitter?

Answer 1

The probability that an internet user uses Twitter and has a wireless connection is 0.135.

Explanation:

Given that,

54% of internet users have a wireless connection.

25% use Twitter to share updates, given that the user have a wireless.

Let A be a user who uses a wireless connection.

Let B be a user who uses Twitter.

P(A)=54%=0.54

P(B|A)= 25%=0.25

`P(B|A)=(P(A\cap B))/(P(A))`

⇒P(A∩B)=P(A)P(B|A)

⇒P(A∩B)= 0.54×0.25

⇒P(A∩B)=0.135

The probability that an internet user uses Twitter and has a wireless connection is 0.135.