Quartiles

Definition

Quartiles are values that divide a data set into four equal parts. They help in understanding the distribution and spread of the data.

5 Must Know Facts For Your Next Test

1. Quartiles are denoted as Q1, Q2 (Median), and Q3.
2. Q1 marks the 25th percentile, where 25% of the data lies below this value.
3. Q2 is the median or the 50th percentile, which divides the data set in half.
4. Q3 represents the 75th percentile, with 75% of the data below this point.
5. The interquartile range (IQR) is calculated as Q3 minus Q1 and measures statistical dispersion.

Review Questions

• What is the significance of Q2 in a quartile distribution?
• How do you calculate the interquartile range (IQR)?
• Which quartile represents the median value in a data set?

Related terms

Percentiles:

Specific points in a dataset that divide it into hundredths.

Median:

The middle value separating the higher half from the lower half of a data sample.

Interquartile Range (IQR): A measure of statistical dispersion between Q1 and Q3.