The mean length of a movie in 2014 was 121 min (https://www.randalolson.com/2014/01/25/movies-arent-actually-much-longer-than-they-used-to-be/) Suppose that the standard deviation is 16 minutes and that the distribution of movie times is normal.
A) Find a time such that only 20% of all movies last more than that time.
B) A theatre randomly selects 15 movies to show. What is the probability that the mean run time for the 15 movies is more than 130 minutes?