The solution can be anything bigger than 13/6.
For example: 3, 4, 5, 6...ect
To answer the question, let x be the cost of each hamburger, y be the cost of each medium fries, and z be the cost of each medium drink. The equations that are described in the problem are,
(Miller ) 4x + 3y = 18.69
(James) x + 2y + z = 8.66
(Steven) 2x + y + z = 10.27
Solving simultaneously for the values of the variables give x = 3.36, y = 1.75, and z = 1.8.
Thus, each hamburger costs $3.36. Each medium fries cost $1.75, and each drink costs $1.8.