the fastest of 10% of the times will qualify. the mean is 51 seconds and the standard deviation is 1.2. what is the MAXIMUM time that will quality for the olympics?

Question

anonymous · Answer

my attempt at this was using the inverse norm...
but i'm not sure whether i should use 10% or 90% for this situation?

anonymous · Answer

Use 10% because faster times have smaller values.

anonymous · Answer

oh so if i want the maximum time.. which would be the slowest possible time. i'd use 90% then?

anonymous · Answer

No, 10% because you want the lowest values to go through because they're the fastest. The maximum time will be the highest value that fits in this group which I believe is -1.282σ.