When Juan commutes to work, the amount of time it takes him to arrive is normally distributed with a mean of 31 minutes and a standard deviation of 4.5 minutes. Using the empirical rule, what percentage of his commutes will be between 22 and 40 minutes?

Which inequality has a dashed boundary line when graphed ?

What is the radius of a circle with an area of 78.5 cubic inches? use 3.14 for pie

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.