14: All you need to do is find the 1/8 mark on the bone at 0 years. Find the bar that looks like it is equal to that 1/8 mark. It’s the bar right before 20. From the choices, the best estimate is d. 17,100.
15: The dependent variable is the amount of dissolved gases. This is because the amount of dissolved gasses is dependent on the air pressure (which would be the independent variable).
