Finding the Fourth Proportional to 12,688.50, 17,510.13 and 7,099.50

Step by Step Solution

1. Step 1: Write the proportion equation
   12,688.50 : 17,510.13 = 7,099.50 : x
2. Step 2: Convert to fraction form
   12,688.50/17,510.13 = 7,099.50/x
3. Step 3: Cross multiply
   12,688.50x = 17,510.13 × 7,099.50
4. Step 4: Simplify right side
   12,688.50x = 124,313,167.94
5. Step 5: Solve for x
   x = 124,313,167.94/12,688.50
6. Step 6: Final answer
   x = 9,797.31