Amanufacturer produces piston rings for an automobile engine. it is known that ring diameter is normally distributed with millimeters. a random sample of 15 rings has a mean diameter of . construct a 99% two-sided confidence interval on the true mean piston diameter and a 95% lower confidence bound on the true mean piston diameter.

Passengers usually start to board their flights 1 hour before the scheduled take off time. the gate will be closed 15 minutes before the takeoff time. jack’s plane is scheduled to take off at 12: 05 a. m. if he arrives at the gate at 11: 45 p. m., can he board the flight?

Which of the following questions is a statistical question? (2 points) how many professional sport leagues are there? where do the professional sport leagues play? how many hours of professional training took place over the weekend? how many hours do you spend each week training for a sports league?

Most animals give birth during a general time of year. this is because animals naturally breed so that their young will be born at the time of year when there will be adequate food supply. the bar graph shows the number of live births of a jackrabbit native to california over the course of year x. based on the data, which of the following would be an appropriate conclusion? a) in general, rabbits give birth during the spring months b) in general, rabbits give birth during the summer months c) in general, m california jackrabbits give birth during the spring months d) in general, california jackrabbits give birth during the summer months