Question

In a survey of students, 60% were in high school and 40% were in middle school. Of the high school students, 30% had visited a foreign country. If a surveyed student is selected at random, what is the probability that the student is in high school and has visited a foreign country?

Answer 1

The probability that the student is in high school and has visited a foreign country is 0.18.

Explanation:

We are given that in a survey of students, 60% were in high school and 40% were in middle school.

Of the high school students, 30% had visited a foreign country.

Let the Probability that students were in high school = P(H) = 60%

Probability that students were in middle school = P(M) = 40%

Also, let F = event that students had had visited a foreign country

So, Probability that high school students had visited a foreign country = P(F/H) = 30%

Now, probability that the student is in high school and has visited a foreign country is given by = Probability that students were in high school
`*` Probability that high school students had visited a foreign country

= P(H)
`*` P(F/H)

= 0.60
`*` 0.30

= 0.18 or 18%