Finding the Fourth Proportional to 12,688.02, 17,505.17 and 7,378.47

Step by Step Solution

1. Step 1: Write the proportion equation
   12,688.02 : 17,505.17 = 7,378.47 : x
2. Step 2: Convert to fraction form
   12,688.02/17,505.17 = 7,378.47/x
3. Step 3: Cross multiply
   12,688.02x = 17,505.17 × 7,378.47
4. Step 4: Simplify right side
   12,688.02x = 129,161,334.80
5. Step 5: Solve for x
   x = 129,161,334.80/12,688.02
6. Step 6: Final answer
   x = 10,179.79