The forced expiratory volume (FEV) is a primary indicator of lung function: it corresponds to the volume of air that can be blown out in one second after inhaling. Researchers are interested in studying n = 264 children ages 11-19; below is a graph of their FEV values. What can we learn from the graph? About 12% of the children had an FEV between 2 and 2.5 . About 71% of the children had an FEV between 3 and 3.5 . FEV is just over 30 for between 20% and 25% of the children. About 30 of the children had an FEV above 4. FEV values range between about 2 and 71 for these children..