An internet site has determined that the length of time that users spend on its site is normally distributed with a mean of 5.9 minutes and a standard deviation of 1.8 minutes.
(a) the probability that a user will stay on the site for more than 7 minutes.
(b) the probability that a user will stay on the site between 2 and 5 minutes.
(c) the 91st percentile for the length of time spent on the site (a time such that 91% of users stay less than that time).
(d ) the probability that a random sample of 30 users has a mean of more than 5.25 minutes on the site.
a) P ( x > 7 ) = 0 . 2 7 0 9 b) P ( 2 < x < 5 ) =... View the full answer