Can you guys help me please Find the measures of the unknown angle
Don’t answer if you do not know .

Asap! i'm not good math and i'm lost.

How long must $542 be invested at a rate of 7% to earn $303.52 in interest? in a easier way

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.