If weight is an explanatory variable and cost is the corresponding response variable, which of these would be represented by the y-axis on a scatterplot?

Which representation has a constant of variation of -2.5

The volume of a spherical hot air balloon v(r) = 4 3 ? r3 changes as its radius changes. the radius is a function of time given by r(t) = 3t. find the instantaneous rate of change of the volume with respect to t at t = 2.

What is the equation of the parabola with focus (-1,-1) and directrix y=1?