Average rate of change is defined by (y^-y)/(t^-t) where the ^ means the final(so final y and final t)
So you'd do (8.75-2.75)/(12-4) which is 6/8 which is 3/4 of a dollar per week
Wow how do you not know how and what kind of bar are you talking about
the answer to this is x= -1
Answer:
we have:

=> r²h = 10.18 = 9.20 = 5.36 = 6.30 = 4.45 = 12.15
=> only r²h = 5.36 satisfy the problem
=> h = 5
h = 5 r = 6
h = 5 r = 6=> d = 12