Marketing and Consumer Behavior Movie trailers are designed to entice audiences by showing scenes from coming attractions. Several trailers are usually shown in a theater before the start of the main feature, and most are available via the Internet. The duration of a movie trailer is approximately normal, with mean 150 seconds and standard deviation 30 seconds.
a. What is the probability that a randomly selected trailer lasts less than 1 minute?
b. Find the probability that a randomly selected trailer lasts between 2 minutes and 3 minutes 15 seconds.
c. Any movie trailer that lasts beyond 4 minutes and 30 seconds is considered too long. What proportion of movie trailers is too long?
d. Find a symmetric interval about the mean such that 99% of all movie trailer durations lie in this interval.