Finding the Fourth Proportional to 12,687.20, 17,507.98 and 7,022.18

Step by Step Solution

1. Step 1: Write the proportion equation
   12,687.20 : 17,507.98 = 7,022.18 : x
2. Step 2: Convert to fraction form
   12,687.20/17,507.98 = 7,022.18/x
3. Step 3: Cross multiply
   12,687.20x = 17,507.98 × 7,022.18
4. Step 4: Simplify right side
   12,687.20x = 122,944,151.89
5. Step 5: Solve for x
   x = 122,944,151.89/12,687.20
6. Step 6: Final answer
   x = 9,690.41