Assume that the waiting time of customers at this

Question

Please, answer must be received within an hour to this question:

The average waiting time for customers at a fast food restaurant is 3.4 minutes. The population standard deviation is 2.5 minutes.

1. Assume that the waiting time of customers at this restaurant follow a normal distribution, what is the probability that a simple random sample of 50 customers will have a sample waiting time of less than 3 minutes?
2. Do we need to make any assumption about the distribution of waiting times for the calculation in Part a? Why or why not?
3. What is the probability that a simple random sample of 100 customers will have a sample waiting time of less than 3 minutes?