The mean amount of time that a bank teller spends with a customer is 3. 1 minutes with a standard deviation of 0.5 minutes. A random sample of 100 customers is selected by a bank manager.

Probability that average amount of time spent by a bank teller with 100 customers is more

than 3.0 minutes is________

Probability that total amount of time spent by a bank teller with 100 customers is more

than 320 minutes is________