Why is this function nonlinear?

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.

Norder to get a certain shade of blue paint, a mixer must have 5 parts white paint to 3 parts blue. if 4 gallons of paint must be mixed, how many gallons of white paint must be used?

Aplane is flying at 32,500 feet. it needs to rise to 36,000 feet in two stages.• in stage 1, it rises 5% of its initial altitude of 32,500 feet.• in stage 2, it rises at a rate of 125 feet per minute.how many minutes does it take for the plane to rise during stage 2?