Guys i really really need help please help me with this assignment its due today -'_'-

Simplify the expression and find the missing terms. the simplest form of has in the numerator and in the denominator.

Empty box + box + empty box fill in the box is equal to 30 how

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.