X1-x2/y1-y2 is what you need for ordered pair
F(x)=x-3 I think but I am not sure
Average weight is when you add up all the weight and divide by the number of objects
if you count the number of x's you will see that you have 10 sandwiches
now add up all the weight
1/8 +1/8+ 1/4+1/4+1/4+1/4+ 3/8+ ....
once you have total weight, divide that number by 10
