To determine whether a business is making enough profit, the following formula is used: (image of formula is provided)
where P is relative profit, S is sales and C is costs. If a company has $340 000 worth of sales and $230 000 of costs, correct to 2 significant figures, calculate the maximum and minimum relative profit to the appropriate accuracy.

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.