How to find interquartile range

The box-and-whisker plot or simply box plot, was invented by John W. Tukey. Tukey, an American mathematician and statistician, introduced the box plot in 1969 as a way to graphically depict groups of numerical data through their quartiles. This method of data visualization has since become a staple in statistical analysis, particularly for displaying the distribution, central value, and spread of datasets. Problem: Determine the Interquartile range for the following set of data: 5, 20, 15, 25, 0, 10, 15, 5, 25, 30, 20 A) 20 B) 25 C) 15