Measures of Position of Grouped Data

Alice made a survey on the number of active Android applications her classmates have. The table summarizes the results. The Class Intervals contain the number of active Android Applications.

How many students were all involved in the survey?

• 30

• 40

• 50

• 60

Answer explanation

Based on the column of Less than Cumulative Frequency (<cf), there are 50 students in total.

What is the size of the class interval?

• 3

• 4

• 5

• 6

Answer explanation

To determine the class size, subtract the upper class from the lower class then add 1.

Sol.: (5 - 1) + 1 = 5

What is the Lower Boundary of the class interval where the third quartile is included?

• 10.5

• 15.5

• 20.5

• 25.5

Answer explanation

The position of the third quartile is in the 27.5th and belongs to the class interval 16 - 20 with <cf of 34. So, the LB is 20.5.

Which of the following is the fourth decile class?

• 1-5

• 6-10

• 11-15

• 15-20

What is the <cf of the class interval where the first quartile is included?

• 1

• 9

• 24

• 34

What does it mean if the first quartlie is 11.67?

• 25% of the students have at least 11 active android applications.

• 11 students have at least 25% of the active android applications.

• 11 students have at most 25%of the active android applications.

• 25% of the students have at most 11 active android applications.

What is the fourth decile of the distribution?

• 14.17

• 15.17

• 16.17

• 17.17

What is the 80th percentile of the distribution?

• 16.1

• 22.81

• 23.81

• 25.5

What does it mean of 95th percentile is 19.75?

• 19% of the students have less than or equal to 65 active android applications.

• 19% of the students have more than or equal to 65 active android applications.

• 65% of the students have less than or equal to 19 active android applications.

• 65% of the students have more than or equal to 19 active android applications.

Which of the following is the 35th percentile?

• 10.33

• 11.33

• 12.33

• 13.33