You borrowed $200 from your brother and he's created 2 plans to help you decide how you want to pay it back. His plans are below. Question 1: How much money did you borrow initially?

Question 2: How much does each plan have you paying back each week (assume there are 4 weeks in each month).

Question 3: Which plan would you choose and why?

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.