Question

in a class of students, the following data table summarizes how many students have a brother or a sister. what is the probability that a student who does not have a brother has a sister?

Explanation:

Identify the given condition and target group

$$ \text{Condition: Student does not have a brother} $$

Find the total number of students meeting the condition

$$ \text{Total (No Brother)} = 2 + 9 = 11 $$

Calculate the conditional probability

$$ P(\text{Sister} \mid \text{No Brother}) = \frac{2}{11} $$

Answer:

\(\frac{2}{11}\)