Quiz Measure of Dispersion Form 4

The following is the stem-and-leaf plot for the scores of two classes. Which statement is the most accurate about the dispersion of the data for both classes?

• Class A has a smaller dispersion than Class B.

• Class B has smaller dispersion than Class A

• Both classes have the same dispersion

• Class A has a larger dispersion than Class B.

The following data represents the number of the books read by two groups of students in a month :

Group A : 2, 3, 4, 6, 7

Group B : 1, 2, 5, 6, 9

A dot plot was constructed for both groups. What is the correct statement about the dispersion of th data?

• Group A has a larger dispersion

• Group B has a smaller dispersion

• Both groups have the same dispersion.

• Group B has a larger dispersion

• m = 14, n = 11

• m = 8, n = 32

• m = 32, n = 8

• m = 8, n = 30

The data below shows the number of goals scored by a football team in 20 matches.

2 2 1 2 4 5 4 4 3 1

1 1 2 5 2 3 3 2 4 3

Calculate the difference between the highest and the lowest number of goals.

• 1

• 2

• 3

• 4

The stem-and-leaf plot shows the heights, in cm, of 20 students.

Determine the difference in height between the tallest and shortest students.

• 31

• 22

• 23

• 30

• p = 80, q = 26

• p = 21, q = 80

• p = 24, q = 31

• p = 80, q = 21

The stem-and-leaf plot shows the marks obtained by 25 students each in class A and class B in a mathematics test.

Based on the stem-and-leaf plot given, which class has wider dispersion? Give your justification.

• Class A, because the difference in marks is bigger

• Class B, because the difference in marks is smaller

• Class B, because the difference in marks is bigger

• Class A, because the difference in marks is smaller

A survey about the time taken to eat breakfast was conducted on two groups of students. The dot plot on the side shows the results of this survey.

Which group showed taking time in breakfast more consistently?

• Group 2 is more consistent since the time difference for Group 2 is larger, more disperse

• Group 1 is more consistent since the time difference for Group 1 is smaller, less disperse

• Group 2 is more consistent since the time difference for Group 2 is smaller, less disperse

• Group 1 is more consistent since the time difference for Group 1 is larger, more disperse

The dot plot below shows the number of passengers who boarded two ferries in a period of 16 days.

Which ferry has a more consistent number of passengers?

• The number of ferry X passengers is more consistent because the disperse difference of ferry X is larger

• The number of ferry Y passengers is more consistent because the disperse difference of ferry Y is smaller

• The number of ferry Y passengers is more consistent because the disperse difference of ferry Y is larger

• The number of ferry X passengers is more consistent because the disperse difference of ferry X is smaller

The incomplete stem-and-leaf plot below shows the scores obtained by 18 students in a Chemistry test. The score for stem "6" is not shown.

Calculate the number of students who obtained at least 60 marks.

• 11 students

• 10 students

• 12 students

• 13 students