In a public health study, a histogram was plotted showing the number of cigarettes smoked per day by each subject, as shown below. The numbers on top of each bar represent its heights. You may assume that the values are spread uniformly across each interval. What is the rst quartile (or the 25 percentile) of the values? p (3.5) % per cigarette Number cl: cigarettes 40 cigarettes 0 between 22 and 23 cigarettes 0 between 36 and 37 cigarettes 0 between 12 and 13 cigarettes O 20 cigarettes