Quartiles (4 regions)
The quartiles divide the data into 4 equal regions. Instead of dividing by 100 in step 2, divide by 4.
Note: The 2nd quartile is the same as the median. The 1st quartile is the 25th percentile, the 3rd quartile is the 75th percentile.
The quartiles are commonly used (much more so than the percentiles or deciles). The TI-82 calculator will find the quartiles for you. Some textbooks include the quartiles in the five number summary.
