Irrational numbers can never be precisely represented in decimal form, why is this?

Which of the following would be a good name for the function that takes the weight of a box and returns the energy needed to lift it?

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.

Ahyperbola centered at the origin has a vertex at (-6,0) and a focus at (10,0)