Tom delivers newspapers every morning. Today he did the following:
Delivered 10 newspapers on Flinders Street
Delivered 6 newspapers on Collins Street
Picked up 20 newspapers from the newsagent
Delivered 15 newspapers on Lonsdale Street
When Tom returned home there were eight newspapers in his bag.
How many did Tom start with?

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.