May you plz awnser this it a lot of points

School has 204 sixth grade students. if the sixth grade is 30% of the total school, how many students are in the middle school?

Your food costs are $5,500. your total food sales are $11,000. what percent of your food sales do the food costs represent?

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.