g A literature review indicates that major earthquakes hit California at a rate of 6 earthquakes per year. You wish to model X, the time in months until the next major earthquake in California, as an exponential distribution. Given the results of the literature review, what arrival rate should you use

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.