Asap find the surface area of this triangular prism

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.

Captain umaima has a ship, the h.m.s. khan. the ship is two furlongs from the dread pirate nadia and her merciless band of thieves. the captain has probability 3/7 of hitting the pirate ship. the pirate only has one good eye, so she hits the captain's ship with probability 2/5. if both fire their cannons at the same time, what is the probability that the captain hits the pirate ship, but the pirate misses.

9is the geometric mean between x and 12