A nurse supervisor found that staff nurses complete a certain task in 10 minutes, on average. If the times required to complete the task are approximately normally distributed with a standard deviation of 3 minutes, find:

a) The percentage of nurses completing the task in less than 5 minutes.
% (e.g. 15.55%)

b) The percentage of nurses requiring more than 10 minutes to complete the task.
% (e.g. 15.55%)

c) The probability that a nurse who has just been assigned the task will take between 8 and 12 minutes to complete it.
(e.g. 0.7512)

d) The slowest 20% are given additional training. What task times qualify staff nurses for such training?
min (e.g. 45.5 min]