What does it mean to say that two variables are negatively correlated?

The ratio pv to nrt is plotted against pressure for ch4 at 0°c and 200°c. why does the curve for 0°c drop below the horizontal line for an ideal gas whereas the curve for 200°c does not?

Henry is an avid reader, he devours 90 pages in half an hour how many pages has henry read per minute?

The focus of parabola is (-4, -5), and its directrix is y= -1. fill in the missing terms and signs in parabolas equation in standard form