Identify the key parts of the graph:
a) rate of change:
b) y-intercept:
c) zero:

The cost per package depends on the weight of the package.

We know that a dependent variable is one which depends on some other variable or the value of the variable is calculated corresponding to the independent variable.

Generally we consider the values on the y-axis or the vertical axis as the dependent values because they are dependent upon the x-value or the value on the horizontal axis.

Here from the graph we may observe that the cost of the package depends on the weight of the package.