I started this and got distracted and never finished and it timed out. Focus Dean.
It's not the best graph; I assume the origin is the apparent origin and the y axis numbers go with the line above them.
This graph is M(V), M(V) is mass in kg of bucket with water volume V in liters
a) the mass of an empty bucket
That's the y intercept, M(0), eyeballing it around .7 kg
Answer: .7 kg
b) the mass of the bucket containing 1 liter of liquid
That's M(1), looks like 1.3 or so
Answer: 1.3 kg
c) the mass of one liter of liquid
That's the difference, M(1)-M(0), about .6 kg. We can get a better estimate from a longer slope, say (.5,1) to (3,3), (3-1)/(3-.5) = .8 kg.
Answer
: 0.8 kg
d) the volume of the liquid in the bucket, if the total mass of bucket with the liquid is 3 kg.
Solve M(V)=3
That has a solution from the graph V=3.
Answer: 3 liters
=18 sides