2. [-18.33 Points] WACKERLYSTAT7 3.8.125. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER Customers arrive at a checkout counter in a department store according to a Poisson distribution at an average of nine per hour. [fit takes approximately ten minutes to serve each customer, find the mean and variance of the total service time in minutes for customers arriving during a lehour period. (Assume that a sufficient number of servers are available so that no customer must wait for service.) [5 it likely that the total service time will exceed 3.5 hours? (Round your answer to three decimal places.) Since P(service time exceeds 3.5 hours) = E , this is event. You may need to use the appropriate appendix table or technology to answer this question. Need Help? @ 3. [18.33 Points] WACKERLYSTAT'I 3.8.127. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER The number of typing errors made by a typist has a Poisson distribution with an average of two errors per page. If more than two errors appear on a given page, the typist must retype the whole page. What is the probability that a randomly selected page does not need to be retyped? (Round your answer to three decimal places.) Z You may need to use the appropriate appendix table or technology to answer this question. Need Help? @