Production Possibility Frontier and Opportunity cost The following is a list of data points on a PPF, answer questions regarding opportunity cost. 






What is the opportunity cost of producing the first 500 Toyota?


The opportunity cost of producing the first 500 Toyota is 600. 
Calculations: 5000-4400


What is the opportunity cost of moving from producing 3725 Lexus to 3950 Lexus? 


Opportunity cost = 1500-1000 = 500 Toyotas


What is the opportunity cost of producing 5000 Lexus? 
The opportunity cost of producing 5000 Lexus is 0.


I am currently learning economics and I came across a homework question I am uncertain about my answers.
Your answers in the first and second questions are correct, as another post noted. However, the last question cannot be answered: we would have to know what would be the number of Toyota produced when production of Lexus is zero, in order to answer that.  

By the way the Labels in your graph are wrong - it should read "Lexus" in the vertical and "Toyota" in the horizontal axis.