I'm gonna need a LOT of help with math- I am once again asking for math help :')

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.

Aparticular telephone number is used to receive both voice calls and fax messages. suppose that 25% of the incoming calls involve fax messages, and consider a sample of 25 incoming calls. (a) what is the expected number of calls among the 25 that involve a fax message?

Ashley recently opened a store that sells only natural ingredients. she wants to advertise her products by distributing bags of samples in her neighborhood. it takes one person 22 minutes to prepare one bag. how many hours will it take to prepare 900900 bags of samples if ashley and 55 of her friends do the work?