The dataset below represents the population densities per square mile of land area in 15 states in the 2010 U.S. Census. What is the interquartile range?

The Interquartile range is 188

Step-by-step explanation:

Missing Data:

1,19,35,43,49,55,63,94,105,110,175,231,239,351,738

Required

Determine the Interquartile range (IQR)

The given data is ordered already.

First, we need to determine the median

For odd number of data

Median = ½(n + 1)th

In this case, n = 15; so

Median = ½(15 + 1)th

Median = ½(16)th

Median = 8th

This implies that the median is at the 8th position.

So, we have:

1,19,35,43,49,55,63 > Lower

(94) Median

105,110,175,231,239,351,738 Upper

Next, we determine the median of the lower and upper sets.

These are called lower quartile (Q1) and upper quartile (Q3) respectively

Lower: 1,19,35,43,49,55,63

Number of data, n = 7

Q1 = ½(n + 1)th

Q1 = ½(7 + 1)th

Q1 = ½(8)th

Q1 = 4th position

From the list of data in the lower set,

Q1 = 43

Upper: 105,110,175,231,239,351,738

Number of data, n = 7

Q3 = ½(n + 1)th

Q3 = ½(7 + 1)th

Q3 = ½(8)th

Q3 = 4th position

From the list of data in the upper set,

Q3 = 231

IQR is then calculated as thus:

IQR = Q3 - Q1

IQR = 231 - 43

IQR = 188