What do the following two equations represent?
-2x – 4y = -3
8x – 4y = -1

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.

Askateboard ramp is in the shape of a right triangle what is the height of the ramp

Out of 50 students surveyed, 16 have a dog. based on these results, predict how many of the 280 students in the school have a dog.