4. Use the table to answer the question.

Question

Class A: 13, 5, 18, 2, 19, 17, 5, 16, 4
Class B: 9, 19, 11, 9, 16, 2, 14, 8, 2
The table shows the times, in minutes, spent completing their math quiz by two different classes. First find the mean times each class spent on the quiz. Then determine the difference between the mean times.
The mean time Class A spent completing the quiz is, _____ minutes.
The mean time Class B spent completing the quiz is _____ minutes.
The mean times Class A and Class B spent completing the quiz differ by _____ minutes.

Answer 1

To find the mean time spent by each class, we add up all the times and divide by the number of students in each class.

For Class A:
(13 + 5 + 18 + 2 + 19 + 17 + 5 + 16 + 4) = 99
Mean time for Class A = 99 / 9 = 11 minutes

For Class B:
(9 + 19 + 11 + 9 + 16 + 2 + 14 + 8 + 2) = 90
Mean time for Class B = 90 / 9 = 10 minutes

The mean time Class A spent completing the quiz is 11 minutes.
The mean time Class B spent completing the quiz is 10 minutes.

The mean times Class A and Class B spent completing the quiz differ by 1 minute.