Question

A survey of a group of seventh graders and a group of teachers at a local middle school asked how many siblings they each have. The dot plots below show the results.

Students
A dot plot titled Students. A number line going from 0 to 9 labeled number of siblings. There are 2 dots above 0, 4 above 1, 7 above 2, 5 above 3, 2 above 4, and 0 above 5, 6, 7, 8, and 9.

Teachers
A dot plot titled Teachers. A number line going from 0 to 9 labeled Number of siblings. There is 1 dot above 0, 3 dots above 1, 2 above 2, 4 above 3, 5 above 4, 3 above 5, 1 above 6, 0 above 7, 1 above 8, and 0 above 9.

What is closest to the difference between the means of the two dot plots?
0.5
1.0
1.5
2.0

Answer 1

1.5

Explanation:

Attached to this answer is the diagram of the box plot described in the question, and the means from the plot are calculated thus;

Students; no. of siblings

student 0 2

student 1 4

student 2 7

student 3 5

student 4 2

Total 20

Mean no. of siblings = (total number of siblings) ÷ (total number of students)

Note that number of students here are the once that had at least one sibling, others without siblings are not used in the calculation, hence 5 students (student-0 to student-4) make up total number of students, while the remaining 4 students (student-4 to student-9) are disregarded.

Therefore, mean = 20 ÷ 5 = 4 siblings.

Answer 2

1.5 is the answer to your question