A(-9, 10)
y
10
Triangle ABC is a right triangle
The length of BC is 5 units.
The area of ABC is
square units.
6
X
-10
-6
2
10
-2
-2
B(7,-2)
5
-6
C(4, -6)
-10

a) There is an 81% probability that a California adult is an internet user, given that he or she is a college graduate.

b) There is a 68% probability that a randomly chosen internet user is a college graduate.

Step-by-step explanation:

The best way to solve this problem is building the Venn Diagram of these sets.

I am going to say that

A is the percentage of California adults that are college graduates.

B is the percentage of California adults that are regular internet users.

We have that:

.

In which a are those who are only college graduates and are those who are both college graduates and regular internet users.

By the same logic, we have that:

In which b are those who are only regular internet users and are those who are both college graduates and regular internet users.

We start finding these values from the intersection:

It is also estimated that 21% of California adults are both college graduates and regular internet users. This means that

26% of all California adults are college graduates. This means that

31% of California adults are regular internet users. This means that

(a) What is the probability that a California adult is an internet user, given that he or she is a college graduate?

The set of college graduates and regular internet users is given by .

The set of college graduates is given by .

So

There is an 81% probability that a California adult is an internet user, given that he or she is a college graduate.

b) Among California adults, what is the probability that a randomly chosen internet user is a college graduate?

The set of college graduates and regular internet users is given by .

The set of internet users in given by .

So

There is a 68% probability that a randomly chosen internet user is a college graduate.