In Linguistics 101, the ratio of the number of girls to the number of boys is $3:2$. When seven more girls join the class, and two boys drop the class, the ratio of the number of girls to the number of boys becomes $5:2$. How many students are in the class after these changes?

Round 0.866 to the nearest hundredth

The graph below represents the number of dolphins in a dolphin sanctuary. select all the key features of this function.

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.