Connor is a 400m runner. He has kept a record of his running times, shown in seconds in the table below. Calculate the following:
his median time
his modal time
seconds
seconds
Connor's 400m times
48.7 48.4
48.5 4.9. 2
48.6 48.5
48.8 4.9.1

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.