Two groups of people were asked to take part in a study. The individuals in group 1 were healthy and the individuals in group 2 had recently recovered from an asthma attack.
In the experiment each individual was asked to breathe in as deeply as they could. They then breathed out via forced expiration.
A study coordinator measured the volume of air that each individual breathed out during forced expiration.
The graph below shows the results.
The FEV (forced expiration volume) is the volume of air that an individual can breathe out within a single second.
Using the graph, calculate the percentage difference in the FEV for group 2 compared with group 1.