Read and try to solve the problem below. A delivery company uses robot dogs to deliver packages in an
office building. The graph shows how long a robot dog can operate
for each hour its battery is charged.
Pick any two points on the line. Find the slope of the line between
these two points. Can you find another pair of points on the line
that gives you a different slope?

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.