Suppose that 65\ee, percent of the 310{,}000310,000310, comma, 000 citizens in a county are registered to vote. A not-for-profit organization takes an SRS of 100100100 of these citizens and finds that 67\gg, percent of those sampled are registered to vote. The organization plans on taking repeated samples like this. What are the mean and standard deviation of the sampling distribution of the proportion of citizens who are registered to vote

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.