Find the range and interquartile range (IQR) of the data set: 2, 4, 6, 8, 10, 12, 14.

Solution

Statistics · Easy

Step 1: Find the range.

The range is the maximum value minus the minimum value.

Maximum = 14
Minimum = 2

Range = 14 - 2 = 12

Step 2: Find the median.

There are 7 values, so the middle value is 8.

The median is 8.

Step 3: Find the first quartile Q1.

Exclude the median and look at the lower half:
2, 4, 6

The median of the lower half is 4.

Therefore:
Q1 = 4

Step 4: Find the third quartile Q3.

The upper half is:
10, 12, 14

The median of the upper half is 12.

Therefore:
Q3 = 12

Step 5: Calculate the interquartile range.

IQR = Q3 - Q1
IQR = 12 - 4
IQR = 8

Therefore, the range is 12 and the IQR is 8.

Result

Range = 12; IQR = 8