Question

which method can be used to find the interquartile range for a set of data?
find the difference between the maximum and minimum values.
find the difference between the upper and lower quartiles.
find the median of the upper half of an ordered data set.
find the sum of the maximum and minimum values.

Explanation:

Step1: Recall the definition of interquartile range

The interquartile range (IQR) is a measure of statistical dispersion.

Step2: Analyze each option

• Option 1: The difference between the maximum and minimum values is the range, not the interquartile range.
• Option 2: By definition, the interquartile range is the difference between the upper quartile ($Q_3$) and the lower quartile ($Q_1$), i.e., $IQR = Q_3 - Q_1$.
• Option 3: The median of the upper half of an ordered data set is the upper quartile ($Q_3$), not the interquartile range.
• Option 4: The sum of the maximum and minimum values has no relation to the interquartile range.

Answer:

Find the difference between the upper and lower quartiles.