Final answer:
The equation for calculating the slope of the feasible frontier in the context of MRT is the ratio of the price of the good on the horizontal axis to the price of the good on the vertical axis.
Step-by-step explanation:
The equation for calculating the slope of the feasible frontier in the context of MRT (Marginal Rate of Transformation) is the ratio of the price of the good on the horizontal axis to the price of the good on the vertical axis. In the given example, the slope is calculated by dividing the price of bus tickets ($0.50) by the price of burgers ($2), which gives a slope of 0.25.