Question

The lunch time spent by 15 employees are plotted in the given line plot. Find the inter quartile range.


Number of employees

• A. 35
• B. 10
• C. 25
• D. 30

Answer 1

The correct option is B 10

The given line plot is


The data set is

15, 15, 20, 25, 25, 25, 25, 30, 30, 30, 35, 35, 45, 45, 45

The data is in ascending order:

15, 15, 20, 25, 25, 25, 25, 30, 30, 30, 35, 35, 45, 45, 45

Let us find the median of the data set.

For a set with an odd number of values, the median is the middle value of the data set when it is arranged in an ascending or descending order.

Median = 30

Let us divide the data into two halves.



Lower half data = 15, 15, 20, 25, 25, 25, 25

Median =25

Hence, lower quartile (Q1) = 25

Upper half data = 30, 30, 35, 35, 45, 45, 45

Median = 35

Hence, upper quartile(Q3) = 35

Inter quartile range(IQR) = Q3 - Q1

= 35 - 25

= 10

Hence, the inter quartile range of the given data = 10