Answer: 28 years
Explanation:
The Interquartile range is calculated by subtracting the 1st quartile (25%) from the third quartile (75%).
From the graph given which shows the cumulative frequencies, you will notice that the third quartile age will be about 40 years.
You will also notice that the first quartile age should be about 12 years.
Interquartile range = 40 - 12 = 28 years.
