Interquartile Range Flashcards

The difference between the upper quartile (Q3) and the lower quartile (Q1). It measures the spread of the middle 50% of the data.

The value that separates the lowest 25% of the data from the rest. It is the median of the lower half of the data.

The value that separates the highest 25% of the data from the rest. It is the median of the upper half of the data.

Find Q1 and Q3, then subtract Q1 from Q3: IQR = Q3 - Q1.

The IQR is used to measure the spread of the middle 50% of the data and is less affected by extreme values (outliers).

Divide the dataset into two halves (excluding the median). Q1 is the median of the lower half.

Divide the dataset into two halves (excluding the median). Q3 is the median of the upper half.

Divide the dataset into two halves. Q1 is the median of the lower half.

Divide the dataset into two halves. Q3 is the median of the upper half.

Outliers are often identified as values that are more than 1.5 × IQR below Q1 or above Q3.