When you finally retire, you want to be able to draw from an account an annual salary of $100,000 for 20 years. Approximately how much should be in your account that has an APR of 5% when you retire, such that you can draw an annual salary of $100,000? Assume an ordinary annuity

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.