Answer:
[tex]P(B|A)=\frac{2}{7}[/tex]
Step-by-step explanation:
The probability of [tex]P(B|A)[/tex] can be read as the probability of event B occurring given event A. In this question, event A occurs when the chosen player is a girl. There are 7 girls on the soccer team. Event B occurs when the chose player plays defense. Since [tex]P(B|A)[/tex] stipulates that event A already occurred, we want the probability of choosing a player who prefers defense from the 7 girls. There are 2 girls who prefer defense, hence [tex]P(B|A)=\boxed{\frac{2}{7}}[/tex].
Alternative:
For dependent events [tex]A[/tex] and [tex]B[/tex], the conditional probability of event B occurring given A is given by:
[tex]P(B|A)=P(B\cap A)\div P(A)[/tex]
[tex]P(B\cap A)[/tex] indicates the intersection of [tex]P(B)[/tex] and [tex]P(A)[/tex]. In this case, it is the probability that both events occur. Since there are 16 kids on the soccer team and only 2 are girls and prefer defense, [tex]P(B\cap A)=\frac{2}{16}=\frac{1}{8}[/tex]. The probability of event A occurring (chosen player is a girl) is equal to the number of girls (7) divided by the number of kids on the team (16), hence [tex]P(A)=\frac{7}{16}[/tex].
Therefore, the probability of event B occurring, given event A occurred, is equal to:
[tex]P(B|A)=\frac{1}{8}\div \frac{7}{16},\\\\P(B|A)=\frac{1}{8}\cdot \frac{16}{7}=\boxed{\frac{2}{7}}[/tex]