17. Shafira had collected £720 in a sponsored event. She gave
of the amount collected to her local youth club.
od
She gave 40% of the amount collected to a children's hospital.
She gave the rest of the money to a mountain rescue group.
(a) How much money did Shafira give to the mountain rescue group?

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.