Calculating cardiac output from table

Stroke volume is the volume of blood pumped out from a ventricle per beat. It is calculated by subtracting the end-systolic volume (i.e. the volume of blood at the end of the contraction, the lowest volume) from the end-diastolic volume (i.e. the volume of blood at the end of filling, the highest volume). You are given the volumes of blood in a ventricle at various points over one cardiac cycle so you can estimate stroke volume by subtracting the lowest volume from the highest volume. If you do it using the values for 0.1s and 0.5s, you get an answer in the range given by the markscheme.