Let's assume the total cost of the computer is "x".
Sandy made a 3% deposit on the computer, which is equivalent to $168. So, we can write:
0.03x = 168
To solve for x, we can divide both sides of the equation by 0.03:
x = 168 ÷ 0.03
x = 5600
Therefore, the total cost of the computer is $5,600.