To find the percentage of 28 from 70:
28/70=0.4
0.4=40%
Let x = the total cost of gas, dollars.
Originally, each of the three friends was to pay x/3 dollars each.
Finally, with two more friends added, the cost became x/5 dollars each.
The savings for each of the original three friends is $11, therefore
x/3 - x/5 = 11
(2x)/15 = 11
x = (11*15)/2 = $82.50
Answer: The total cost of gas is $82.50
The absolute deviation for this problem is 2.2.
