Invested 28, 000 in two accounts, one yielding 8% and the other at 9%. if i receive a total of 2,440 in intrest at the end of the year, how much did i invested in each account

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 one is the correct answer, and why?

What is the approximate value of  q  in the equation below? –1.613–1.5220.5853.079