sam's garage door installs new garage doors on a residential home. suppose the installation time follows a uniform distribution with a minimum time of 120 minutes and a maximum time of 320 minutes. show all work

a.) on average, how long will it take to install a garage door?

b.) what is the probability that an installation will require at least 3 hours to complete? (answer percentage, 2 decimal places)

c.) 80% of the time, the installation time for a garage door will be less than how many minutes? (answer in minutes)