Firefighters are running drills all week. one drill has them climbing ladders up to 3rd story windows. if the closest they can get the base of their ladder to the practice house is 9 feet and the ladder needs to reach up 38 feet, how long must the ladder be?

! i'm not too sure what i have to do

An automobile assembly line operation has a scheduled mean completion time, μ, of 12 minutes. the standard deviation of completion times is 1.6 minutes. it is claimed that, under new management, the mean completion time has decreased. to test this claim, a random sample of 33 completion times under new management was taken. the sample had a mean of 11.2 minutes. assume that the population is normally distributed. can we support, at the 0.05 level of significance, the claim that the mean completion time has decreased under new management? assume that the standard deviation of completion times has not changed.