If: f(x) = 2.50x + 15; then: f(6) = show work

The square pyramid has a volume of 441 cubic inches. what is the value of x? 1/7x is the height x is the base

Can somebody 1. what is the formula for finding the vertical distance between two points on a coordinate plane?

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.