I'd seriously appreciate it if anyone could asap! i'll give brainliest! mary wants to buy a dress which costs $200 from the money she gets by working overtime. she has already saved up $50 for the dress. the following graph below shows the money she will get by working extra hours. how many extra hours does mary need to work so that she can buy the dress of her choice? 16 hours 10 hours 14 hours 12 hours

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.