The dot plot shows the number of people that live in the household of each surveyed student. Each plot represents the answer of one student in the class.
There are 25 dots on the graph, which means that the sample size is 25.
You need to determine the percentage of the class that has a household of 3 or fewer students. To do so, first count the number of students that have a household of two and three people:
2 people in the household: 3
3 people in the household: 4
→ the number of students that have a household of three or fewer people is 7.
Next, divide the number of students with 3 or fewer people in their household by the total number of students surveyed and multiply it by 100 to determine the percentage it represents:
The percent of the class that has a household of 3 or fewer people is 28% (option D)