Question

It is estimated that 27% of all Callfornia adults are college graduates and that 31% of California adults are regular internet users. It is also estimated that 21% of California adults are both college graduates and regular internet users. Answer the questions below. (If necessary, consult a list of formulas.) (a) Among California adults, what is the probability that a randomly chosen internet user is a college graduate? Round your answer to 2 decimal places. $ E (b) What is the probability that a California adult is an internet user, given that he or she is a college graduate? Round your answer to 2 decimal places

Answer 1

Let , A be the event that the California adults is a college graduates and B be the event that the California adults are regular internet users.

Given : P(A)=27%=0.27

P(B)=31%=0.31

$P(A\cap B)=21\%=0.21$

Now ,

a) $P(A\cap B)=21\%=0.21$

Therefore , the probability that the randomly choosen internet user is a college graduate is 0.21

b) By using definition of conditional probability ,

$P(B|A)=\frac{P(B\cap A)}{P(A)}=\frac{P(A\cap B)}{P(A)}=\frac{0.21}{0.27}=0.78$

Therefore , the probability that a california adult is an internet user , given that he or she is a college graduate is 0.78