Respuesta :

First put the data in order from least to greatest.....

4, 6, 8, 10, 11, 12, 18, 20
^     ^         ^          ^      ^
Min Q1    Med     Q3   Max 

Minimum -  4 
First quartile -  7
Median -  10.5
Third quartile -  15
Maximum -  20

Hope this helps! :)