Please help will give brainliest 7th grade math

Two variables, x and y, vary inversely, and x=12 when y=4. what is the value of y when x=3?

Use multiples to write two fractions equivalent to 7/9. 14/18, 8/10 6/8, 21/27 10/12, 28/36 14/18, 21/27

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.