Reggie deposited $1200 into an account that earns 5% compound interest yearly if he does not deposit any more to the account or take any money out of the account how much interest will Reggie earn on his investment at the end of four years round your answer to the nearest whole number

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.