Kyle is draining a 64,000 gallon swimming pool. The pool has 16,000 gallons left after 6 hours. Write a proportion that Kyle can use to find out how much longer will take the pool to fully drain.

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.