DeAndre‘s coffee shop makes a blend that is a mixture of two types of coffee. Type a coffee cost DeAndre $5.80 per pound, and type the coffee cost $4.45 per pound. This months Lynn used three times as many pounds of tight be coffee as type of egg, for a total cost of $536.20. How many pounds of type a coffee were used?

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.