Someone please help quickly. If you were to randomly survey 20 people at 50 randomly chosen high schools, would this be a random sample? Why or why not?

Q1 which of the following is a factor of a)37 b)53 c)62 d)82 q2) if the sum of 2016 different whole numbers is odd. at most how many of the numbers can be even a)0 b)1 c)2014 d)2015

It takes jonas 7 1/4 minutes to run the mile. it takes mario 8 5/12 to run the mile. how much faster is jonas than mario? 5/6 minute 1 1/3 minutes 1 1/6 minutes 1 1/2 minutesi will give points and brainlest

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.