A probability from a frequency table compares the count in the requested category with the number of people who could be chosen. Read the category’s count, divide by the entire group, and use Desmos to match a decimal choice. Don’t add another category unless the question includes it.
Hints
- Hint 1
A frequency is the number of students in a category. Follow the Cat row to its count. That number goes on top of the probability fraction, but it isn’t the probability by itself.
- Hint 2
The sample space is everyone who could be chosen. Since the selection is from all surveyed students, put the total number surveyed under the cat count. What fraction should you divide?
Step-by-step
Compare the cat count with the whole class
Step 1Find the matching count
The frequency in the Cat row is the number of students who chose cat. The row shows 9 students, so is the matching count.
- Step 2
Write the probability fraction
The student is chosen from all students, not from one pet category. Probability is the matching count divided by the whole group. So write: .
- Step 3
Convert the fraction to a decimal
Type into Desmos. It shows , which is the same as . So the probability of choosing a student who chose cat is . Choice B.