Finding the Fourth Proportional to 22,378.63, 30,878.47 and 12,688.12

Step by Step Solution

1. Step 1: Write the proportion equation
   22,378.63 : 30,878.47 = 12,688.12 : x
2. Step 2: Convert to fraction form
   22,378.63/30,878.47 = 12,688.12/x
3. Step 3: Cross multiply
   22,378.63x = 30,878.47 × 12,688.12
4. Step 4: Simplify right side
   22,378.63x = 391,789,732.78
5. Step 5: Solve for x
   x = 391,789,732.78/22,378.63
6. Step 6: Final answer
   x = 17,507.32