Originally Posted by kingofsurvivorbb
i'm not really sure how to do the problem.
do i do 25/15 = 1.67 std devation.
so use the z score for 1.67?
This looks right to me. Comes out to 90.5% (0.905 is the requested form).
As an aside, the net is too damn small. An interesting followup question would be for you to calculate the needed size to ensure, say, 99.99% chance of hitting the net, so the guy only dies once in 10,000 tries. I think that would be a reasonable standard.