A researcher was interested in the mean wait time in South Carolina emergency rooms. 3 emergency rooms were randomly selected and all of the wait times were entered into the data set. This is an example of sampling.

Select one:
simple random
stratified
convenience
cluster

What is the ratio for the surface areas of rectangle prisims shown below given that they are similar and that the ratio of their edge lengths is 7: 3

Which statement accurately explains whether a reflection over the y-axis and a 270° counterclockwise rotation would map figure acb onto itself? a coordinate plane with figure acb with point a at 1, 1, c at 3, 4 and b at 5, 1 yes, a″c″b″ is located at a″(1, 1), c″(4, 3), and b″(1, 5) yes, a″c″b′ is located at a″(1, 1), c″(3, 4), and b″(5, 1) no, a″c″b″ is located at a″(1, 1), c″(4, 3), and b″(1, 5) no, a″c″b″ is located at a″(1, 1), c″(3, 4), and b″(5, 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.