You have a circle that depicts the equator of the earth saw from top (from the artic polar circle). knowing that the equator is in 0º of latitude, the tropic of cancer in 23º of latitude, and the diameter of the circle that depicts the equator is 4 cm, how can i mesure in the same scale where is the tropic of cancer?

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.