Joanie believes that you cannot use cross products to solve the proportion 50/3=75/x for x. she says that if you multiply both sides of the equation by x, you get 50x/3=75. then, if you multiply both sides of the equation by 3, you get 50x=75, which is a different equation than you would get if you cross multiplied. what mistake did joanie make in her reasoning?

Aboat costs 19200 and decreases in value by 12% per year. how much will it cost in 5 years

Ineed to know the answer to this algebra question.

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.