The open end of a garden hose is directed horizontally, at a height of 1.25 m above the ground. Water issues from the hose and follows a falling parabolic trajectory to strike the ground 2.43 m away. A gardener holding the hose wishes to water some plants that are 5.12 m distant. What fraction of the hose end should she cover with her thumb? Assume that she continues to hold the hose end horizontally at the same height, and be careful to tell the fraction covered, not the fraction left open.