Find the geometric mean of the pair of numbers 5 and 6

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.

Given sin28.4=.4756, cos28.4=.8796, and tan28.4=.5407 find the cot of 61.6

In a newspaper, it was reported that yearly robberies in springfield were up 25% to 265 in 2013 from 2012. how many robberies were there in springfield in 2012?