Question

What is the interquartile range of the following data set? 5, 6, 7, 3, 4, 5, 6, 8, 7

Answer 1

Interquartile range = Q3 - Q1 = 7 - 4.5 = 2.5

Explanation:

Before we calculate interquartile range, you should understand that:

Interquartile range is the range between Q3 and Q1 of a dataset i.e Q3 - Q1

Where,

Q1 is the middle value in the first half of the data set and

Q3 is the middle value in the second half of the data set.

So to calculate the interquartile range we find the Q3 and Q1

5, 6, 7, 3, 4, 5, 6, 8, 7

So in the data set to find Q1 and Q3, we rearrange the dataset and divide it into First half and second half.

3, 4, 5, 5, 6, 6, 7, 7, 8

First half = 3, 4, 5, 5

Second half = 6, 7, 7, 8

So

Q1 = (4+5)/2 = 4.5

Q3 = (7+7)/2 = 7

Interquartile range = Q3 - Q1 = 7 - 4.5 = 2.5

Answer 2

2.5

Explanation:

lower quartile.

3, 4, 5, 5, 6, 6, 7, 7, 8

median = 6

lower quartile 1/4th position

(4+5)/2 = 4.5

Upper quartile 3/4th position

(7+7)/2 = 7

Interquartile range = upper quartile - lower quartile

= 7 - 4.5

= 2.5