Hello help pls :3333333 I only need the answer to part B which asks about the mean

Afactory makes propeller drive shafts for ships. a quality assurance engineer at the factory needs to estimate the true mean length of the shafts. she randomly selects four drive shafts made at the factory, measures their lengths, and finds their sample mean to be 1000 mm. the lengths are known to follow a normal distribution whose standard deviation is 2 mm. calculate a 95% confidence interval for the true mean length of the shafts. input your answers for the margin of error, lower bound, and upper bound.

What is the radius of a circle with an area of 78.5 cubic inches? use 3.14 for pie

Will mark name all segments skew to bc