A water tank is draining. The volume of the water in the tank, in gallons, is a linear function of the amount of time it has been draining, in hours. It can be modeled using
the equation V (t) = -12.8t +685, where V is the volume and t is the time.
Explain what the values -12.8 and 685 mean in the context of this problem. Be sure to
use units in your response.

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.

What is the value of x? enter your answer in the box.

Explain how to graph a scatterplot and its regression line using a regression calculator.