Final answer:
To find the interquartile range (IQR), arrange the data in ascending order and find the medians of the lower and upper halves of the data set. Subtract the lower median (Q1) from the upper median (Q3) to find the IQR.
Step-by-step explanation:
The interquartile range (IQR) is a measure of the spread of data in a data set. It is calculated by finding the difference between the upper quartile and the lower quartile. To find the IQR for the given data set {18, 15, 16, 22, 24, 12, 17, 25, 16, 19, 20, 17}, you need to first find the upper quartile (Q3) and lower quartile (Q1), then subtract Q1 from Q3.
To find Q1, arrange the data in ascending order and find the median of the lower half. In this case, the lower half is {12, 15, 16, 16, 17, 17}. The median of the lower half is 16. To find Q3, arrange the data in ascending order and find the median of the upper half. In this case, the upper half is {18, 19, 20, 22, 24, 25}. The median of the upper half is 21.5. Finally, subtract Q1 (16) from Q3 (21.5) to find the IQR, which is 5.5.