For 15 its just the shape, if you draw a shape based on the dots, compare them. Like left one is a bit taller and wider.
16: for left one median is 8 i think. Right one is 9.5 i think
17: for left one, 13 is an outlier, for right one, 11.5 is outliner. You just write the beginning and ends including and not including those outliers.
18: people in group A were kids and people in group B were adults because their shoe sizes are much higher.