How much time (in seconds) will elapse before the fastest 10% of the downloads of an OurCampus!…

How much time (in seconds) will elapse before the fastest 10% of the downloads of an OurCampus! video are complete?
What are the lower and upper values of X, symmetrically distributed around the mean, that include 95% of the download times for a video at the OurCampus! website
Instead of looking up cumulative probabilities in a table, you can use Excel or Minitab to compute normal probabilities