Agroup of preschoolers has 16 boys and 66 girls. what is the ratio of boys to all students

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.

Which is the graph of the function f(x) = x2 + 2x – 6?

If the maglev train travels at a constant speed of 480 kilometer per hour for 1/4 hour how far does the train travel