Lancé le 26 novembre 2011, le Rover Curiosity de la Nasa est chargé d'analyser la planète Mars. il a atterri sur la planète rouge le 6 août 2012, parcourant ainsi une distance d'environ 560 millions de kilomètres en 255 jours. quelle est la durée du vol?

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.