Final answer:
The absolute value of the slope of a budget line is 0.25.
Step-by-step explanation:
The absolute value of the slope of a budget line represents the rate at which one good must be given up to obtain more of the other good. In this case, since the slope is -0.25, it means that for every 4 bus tickets Alphonso buys, he must give up 1 burger. The absolute value of the slope is | -0.25 | = 0.25.