1. The amount of time a supervisor devotes to their new employees to obtain high operational efficiency is a random variable normally distributed with an average of 7.5 hours and a standard deviation of 2.1 hours.
   1. What proportion of supervisors dedicates more than 10 hours per week for their new employees to achieve high operational efficiency?
   2. Find the probability that supervisors will spend 7-9 hours to get your new employees to achieve high operational efficiency.
   3. What proportion of supervisors spends less than 3 hours for their new employees to achieve high operational efficiency?