Wang Yan drove her truck. The fuel remaining in the truck's tank (in liters) as a function of distance (in kilometers) is graphed. What is the approximate average fuel consumption rate, between the 100^\text{th}100 th
100, start superscript, start text, t, h, end text, end superscript kilometer and the 400^\text{th}400
th
400, start superscript, start text, t, h, end text, end superscript kilometer?