Avideo game has been developed whereby the player must earn a certain number of experience points before progressing to the next level. on level 1, a player must earn 1 experience point. on level 2, a player must earn 7 experience points. on level 3, a player must earn 15 experience points. on level 4, a player must earn 25 experience points. how many experience points must a player earn on level 7?

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.