Question

Numa turma, 5% dos homens e 2% das mulheres tem mais de 1,60m de altura. Por outro lado, 60% dos estudantes são homens. Se um estudante é selecionado aleatoriamente e tem mais de 1,60m de altura, qual a probabilidade de que o estudantes seja mulher?

Answer 1

0.8%

Explanation:

Because they are two independent events, the final probability is the product of the probability of each event.

First event:

The complement of a student being male is that he is female.

Therefore, if 60% is male, the remaining 100% is 40%, meaning that 40% of the students are female.

Second event:

If she's taller than 5'4", we're told she has a 2% chance of being a woman.

Therefore the final probability is:

0.4*0.02 = 0.008

That is, the probability that it is female and that it is over 1.6 meters tall is 0.8%.