Answer:
It is 91% more likely that the tree was atmost 500 yards from the river.
We are given with distance and height of 100 young trees near a river.
From that table, in total there are 55 trees which grow more than 3 ft during the year.
And among those 55 trees, 50 trees are atmost 50 yards from river.
Hence it is ≈91% more likely that the tree was atmost 50 yards from the river.