A roof in the shape of a half-cylinder covers the a local soccer field so kids can play soccer year-round. The building has a length of 80 feet and a width of 50 feet. Calculate the lateral
area of the roof. Use = 3.14.

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.