To find the probability that someone is in the 11th grade and prefers soccer, we need to determine the number of students who meet both criteria (11th grade and soccer preference) and then identify the total number of students surveyed, which will be in the denominator.
From the table:
- The number of students in the 11th grade who prefer soccer is 16.
The total number of students surveyed, which is the sum of all the students (regardless of grade or sport preference), is given as 100.
Therefore, the probability \( P \) of selecting a student who is in the 11th grade and prefers soccer can be expressed as:
\[ P(\text{11th Grade and Soccer}) = \frac{\text{Number of 11th Grade Soccer Preferencers}}{\text{Total Number of Students}} = \frac{16}{100} \]
Thus, the value that must be in the numerator for this probability is 16.