If n`(x)=1/1+x^2, p(x)=tan(x), Then (n•p)`(x)=1, why??

This is different from the first one can someone me

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.

We have 339 ounces of jam to be divided up equally for 12 people how muny ounces will each person get