Aparking spaces reserved for motorcycles, cars, and vans. there are five more spaces reserved for vans than for motorcycles. there are three times as many car spaces as van and motorcycle spaces combined. if the parking lot has 180 total reserved spaces, how many of each tyoe are there?

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.