probability and statistics

You are told that flight times from Newark,NJ to Greenville,SC are uniformly distrubuted from 2.5 to 3.5 hours with standard deviation 0.289 hours.

1. What proportion of flights take between 2.75 and 3.25 hours?

2. The estimated arrival time for the next flight is 6:00 PM. If the plane left at 3:15PM what is the probability that it will be late?

3. Write the sampling distrubution for the mean flight time of a sample of 16 flights from newark to greenville

4.  use part c to estimate. Interpret your answers in the context of the problem. For example, is this an unusual event?