Quartile1 Command

Quartile1( <List of Raw Data> ): Determines the lower quartile of the list elements.

Quartile1({1, 2, 3, 4}) yields 1.5.

Quartile1( <List of Numbers>, <List of Frequencies> ): Determines the lower quartile of the list elements considering the frequencies.

Quartile1({1, 2, 3, 4}, {3, 2, 4, 2)) yields 1.

GeoGebra uses the Moore & McCabe (2002) method to calculate quartiles, see http://mathworld.wolfram.com/Quartile.html