Alec runs 12 laps in the same time as Siri runs 16 laps. They begin running at the same time. How far has Siri run when Alec completes 9 laps I need help asap

Find the value of x for which the lines are parallel.

Is this a polynomial function? i need to know asap

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.