Finding the Fourth Proportional to 42,276.40, 63,395.89 and 12,688.55

Step by Step Solution

1. Step 1: Write the proportion equation
   42,276.40 : 63,395.89 = 12,688.55 : x
2. Step 2: Convert to fraction form
   42,276.40/63,395.89 = 12,688.55/x
3. Step 3: Cross multiply
   42,276.40x = 63,395.89 × 12,688.55
4. Step 4: Simplify right side
   42,276.40x = 804,401,920.06
5. Step 5: Solve for x
   x = 804,401,920.06/42,276.40
6. Step 6: Final answer
   x = 19,027.21