After a campaign to encourage students to take precautions a

After a campaign to encourage students to take precautions against skin cancer, in a certain high school class consisting of 35 girls and 45 boys, it is observed that 24 girls and 26 boys take precautions as measured by a survey to elicit how often they wear sunscreen, sunglasses and hats for protection against the sun. What is the probability that a student picked at random takes precautions against skin cancer (by wearing sunscreen, sunglasses and a hat), given that the student is a boy?

Solution

After a campaign to encourage students to take precautions against skin cancer, in a certain high school class consisting of 35 girls and 45 boys, it is observed that 24 girls and 26 boys take precautions as measured by a survey to elicit how often they wear sunscreen, sunglasses and hats for protection against the sun.

Thus, the probability that a student picked at random takes precautions against skin cancer given that the student is a boy is:

(26/45)*(35/80)/(45/(45+35))

=0.58*0.4375/0.5625

=0.451