A candy maker makes two sizes of candies. Using the smaller size, a full jar will contain 120 pieces of candy. Using the larger candies a jar will contain 80 pieces of candy. The candy maker has a strict rule that no jars will contain a mix of small and large candies. If a store has room for 15 jars and they want 1560 total pieces of candy, how many jars will contain smaller candies?

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.