On Monday, Harold picked up six donuts and five large coffees for the office staff. He
paid $7.35. On Tuesday, Melinda picked up two donuts and three large coffees for the
office staff. She paid $3.53. What is the cost of one donut? What is the cost of one
large coffee?

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.